27 files changed, 298 insertions, 290 deletions
diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index b26de523ab70..51e1904ac4c7 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -2143,6 +2143,7 @@ void intel_crt_init(struct drm_device *dev)
      <title>fbdev Helper Functions Reference</title>
 !Pdrivers/gpu/drm/drm_fb_helper.c fbdev helpers
 !Edrivers/gpu/drm/drm_fb_helper.c
+!Iinclude/drm/drm_fb_helper.h
    </sect2>
    <sect2>
      <title>Display Port Helper Functions Reference</title>
diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c
index 3e6584b940dc..34931fe7d2c5 100644
--- a/drivers/gpu/drm/ast/ast_fb.c
+++ b/drivers/gpu/drm/ast/ast_fb.c
@@ -40,6 +40,7 @@
 #include <drm/drmP.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_fb_helper.h>
+#include <drm/drm_crtc_helper.h>
 #include "ast_drv.h"
 static void ast_dirty_update(struct ast_fbdev *afbdev,
@@ -145,9 +146,10 @@ static int astfb_create_object(struct ast_fbdev *afbdev,
        return ret;
 }
-static int astfb_create(struct ast_fbdev *afbdev,
+static int astfb_create(struct drm_fb_helper *helper,
                        struct drm_fb_helper_surface_size *sizes)
 {
+        struct ast_fbdev *afbdev = (struct ast_fbdev *)helper;
        struct drm_device *dev = afbdev->helper.dev;
        struct drm_mode_fb_cmd2 mode_cmd;
        struct drm_framebuffer *fb;
@@ -248,26 +250,10 @@ static void ast_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
        *blue = ast_crtc->lut_b[regno] << 8;
 }
-static int ast_find_or_create_single(struct drm_fb_helper *helper,
-                                          struct drm_fb_helper_surface_size *sizes)
-{
-        struct ast_fbdev *afbdev = (struct ast_fbdev *)helper;
-        int new_fb = 0;
-        int ret;
-        if (!helper->fb) {
-                ret = astfb_create(afbdev, sizes);
-                if (ret)
-                        return ret;
-                new_fb = 1;
-        }
-        return new_fb;
-}
 static struct drm_fb_helper_funcs ast_fb_helper_funcs = {
        .gamma_set = ast_fb_gamma_set,
        .gamma_get = ast_fb_gamma_get,
-        .fb_probe = ast_find_or_create_single,
+        .fb_probe = astfb_create,
 };
 static void ast_fbdev_destroy(struct drm_device *dev,
@@ -314,6 +300,10 @@ int ast_fbdev_init(struct drm_device *dev)
        }
        drm_fb_helper_single_add_all_connectors(&afbdev->helper);
+        /* disable all the possible outputs/crtcs before entering KMS mode */
+        drm_helper_disable_unused_functions(dev);
        drm_fb_helper_initial_config(&afbdev->helper, 32);
        return 0;
 }
diff --git a/drivers/gpu/drm/cirrus/cirrus_fbdev.c b/drivers/gpu/drm/cirrus/cirrus_fbdev.c
index 3daea0f638c3..e25afccaf85b 100644
--- a/drivers/gpu/drm/cirrus/cirrus_fbdev.c
+++ b/drivers/gpu/drm/cirrus/cirrus_fbdev.c
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <drm/drmP.h>
 #include <drm/drm_fb_helper.h>
+#include <drm/drm_crtc_helper.h>
 #include <linux/fb.h>
@@ -120,9 +121,10 @@ static int cirrusfb_create_object(struct cirrus_fbdev *afbdev,
        return ret;
 }
-static int cirrusfb_create(struct cirrus_fbdev *gfbdev,
+static int cirrusfb_create(struct drm_fb_helper *helper,
                           struct drm_fb_helper_surface_size *sizes)
 {
+        struct cirrus_fbdev *gfbdev = (struct cirrus_fbdev *)helper;
        struct drm_device *dev = gfbdev->helper.dev;
        struct cirrus_device *cdev = gfbdev->helper.dev->dev_private;
        struct fb_info *info;
@@ -219,23 +221,6 @@ out_iounmap:
        return ret;
 }
-static int cirrus_fb_find_or_create_single(struct drm_fb_helper *helper,
-                                           struct drm_fb_helper_surface_size
-                                           *sizes)
-{
-        struct cirrus_fbdev *gfbdev = (struct cirrus_fbdev *)helper;
-        int new_fb = 0;
-        int ret;
-        if (!helper->fb) {
-                ret = cirrusfb_create(gfbdev, sizes);
-                if (ret)
-                        return ret;
-                new_fb = 1;
-        }
-        return new_fb;
-}
 static int cirrus_fbdev_destroy(struct drm_device *dev,
                                struct cirrus_fbdev *gfbdev)
 {
@@ -267,7 +252,7 @@ static int cirrus_fbdev_destroy(struct drm_device *dev,
 static struct drm_fb_helper_funcs cirrus_fb_helper_funcs = {
        .gamma_set = cirrus_crtc_fb_gamma_set,
        .gamma_get = cirrus_crtc_fb_gamma_get,
-        .fb_probe = cirrus_fb_find_or_create_single,
+        .fb_probe = cirrusfb_create,
 };
 int cirrus_fbdev_init(struct cirrus_device *cdev)
@@ -291,6 +276,9 @@ int cirrus_fbdev_init(struct cirrus_device *cdev)
                return ret;
        }
        drm_fb_helper_single_add_all_connectors(&gfbdev->helper);
+        /* disable all the possible outputs/crtcs before entering KMS mode */
+        drm_helper_disable_unused_functions(cdev->dev);
        drm_fb_helper_initial_config(&gfbdev->helper, bpp_sel);
        return 0;
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 9c797f6fea75..f17077307c65 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -68,9 +68,23 @@ void drm_modeset_unlock_all(struct drm_device *dev)
        mutex_unlock(&dev->mode_config.mutex);
 }
 EXPORT_SYMBOL(drm_modeset_unlock_all);
+/**
+ * drm_warn_on_modeset_not_all_locked - check that all modeset locks are locked
+ * @dev: device
+ */
+void drm_warn_on_modeset_not_all_locked(struct drm_device *dev)
+{
+        struct drm_crtc *crtc;
+        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
+                WARN_ON(!mutex_is_locked(&crtc->mutex));
+        WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
+}
+EXPORT_SYMBOL(drm_warn_on_modeset_not_all_locked);
 /* Avoid boilerplate.  I'm tired of typing. */
 #define DRM_ENUM_NAME_FN(fnname, list)                          \
        char *fnname(int val)                                   \
diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
index 3742bc96421e..e851658f87d5 100644
--- a/drivers/gpu/drm/drm_fb_cma_helper.c
+++ b/drivers/gpu/drm/drm_fb_cma_helper.c
@@ -275,23 +275,8 @@ err_drm_gem_cma_free_object:
        return ret;
 }
-static int drm_fbdev_cma_probe(struct drm_fb_helper *helper,
-        struct drm_fb_helper_surface_size *sizes)
-{
-        int ret = 0;
-        if (!helper->fb) {
-                ret = drm_fbdev_cma_create(helper, sizes);
-                if (ret < 0)
-                        return ret;
-                ret = 1;
-        }
-        return ret;
-}
 static struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
-        .fb_probe = drm_fbdev_cma_probe,
+        .fb_probe = drm_fbdev_cma_create,
 };
 /**
@@ -333,6 +318,9 @@ struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
        }
+        /* disable all the possible outputs/crtcs before entering KMS mode */
+        drm_helper_disable_unused_functions(dev);
        ret = drm_fb_helper_initial_config(helper, preferred_bpp);
        if (ret < 0) {
                dev_err(dev->dev, "Failed to set inital hw configuration.\n");
@@ -389,8 +377,10 @@ EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini);
 */
 void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma)
 {
+        drm_modeset_lock_all(dev);
        if (fbdev_cma)
                drm_fb_helper_restore_fbdev_mode(&fbdev_cma->fb_helper);
+        drm_modeset_unlock_all(dev);
 }
 EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode);
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 0c6e25e979dd..59d6b9bf204b 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -52,9 +52,36 @@ static LIST_HEAD(kernel_fb_helper_list);
 * mode setting driver. They can be used mostly independantely from the crtc
 * helper functions used by many drivers to implement the kernel mode setting
 * interfaces.
+ *
+ * Initialization is done as a three-step process with drm_fb_helper_init(),
+ * drm_fb_helper_single_add_all_connectors() and drm_fb_helper_initial_config().
+ * Drivers with fancier requirements than the default beheviour can override the
+ * second step with their own code.  Teardown is done with drm_fb_helper_fini().
+ *
+ * At runtime drivers should restore the fbdev console by calling
+ * drm_fb_helper_restore_fbdev_mode() from their ->lastclose callback. They
+ * should also notify the fb helper code from updates to the output
+ * configuration by calling drm_fb_helper_hotplug_event(). For easier
+ * integration with the output polling code in drm_crtc_helper.c the modeset
+ * code proves a ->output_poll_changed callback.
+ *
+ * All other functions exported by the fb helper library can be used to
+ * implement the fbdev driver interface by the driver.
 */
-/* simple single crtc case helper function */
+/**
+ * drm_fb_helper_single_add_all_connectors() - add all connectors to fbdev
+ *                                             emulation helper
+ * @fb_helper: fbdev initialized with drm_fb_helper_init
+ *
+ * This functions adds all the available connectors for use with the given
+ * fb_helper. This is a separate step to allow drivers to freely assign
+ * connectors to the fbdev, e.g. if some are reserved for special purposes or
+ * not adequate to be used for the fbcon.
+ *
+ * Since this is part of the initial setup before the fbdev is published, no
+ * locking is required.
+ */
 int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
 {
        struct drm_device *dev = fb_helper->dev;
@@ -163,6 +190,10 @@ static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
        crtc->funcs->gamma_set(crtc, r_base, g_base, b_base, 0, crtc->gamma_size);
 }
+/**
+ * drm_fb_helper_debug_enter - implementation for ->fb_debug_enter
+ * @info: fbdev registered by the helper
+ */
 int drm_fb_helper_debug_enter(struct fb_info *info)
 {
        struct drm_fb_helper *helper = info->par;
@@ -208,6 +239,10 @@ static struct drm_framebuffer *drm_mode_config_fb(struct drm_crtc *crtc)
        return NULL;
 }
+/**
+ * drm_fb_helper_debug_leave - implementation for ->fb_debug_leave
+ * @info: fbdev registered by the helper
+ */
 int drm_fb_helper_debug_leave(struct fb_info *info)
 {
        struct drm_fb_helper *helper = info->par;
@@ -239,10 +274,21 @@ int drm_fb_helper_debug_leave(struct fb_info *info)
 }
 EXPORT_SYMBOL(drm_fb_helper_debug_leave);
+/**
+ * drm_fb_helper_restore_fbdev_mode - restore fbdev configuration
+ * @fb_helper: fbcon to restore
+ *
+ * This should be called from driver's drm ->lastclose callback
+ * when implementing an fbcon on top of kms using this helper. This ensures that
+ * the user isn't greeted with a black screen when e.g. X dies.
+ */
 bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper)
 {
        bool error = false;
        int i, ret;
+        drm_warn_on_modeset_not_all_locked(fb_helper->dev);
        for (i = 0; i < fb_helper->crtc_count; i++) {
                struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
                ret = drm_mode_set_config_internal(mode_set);
@@ -253,6 +299,10 @@ bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper)
 }
 EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode);
+/*
+ * restore fbcon display for all kms driver's using this helper, used for sysrq
+ * and panic handling.
+ */
 static bool drm_fb_helper_force_kernel_mode(void)
 {
        bool ret, error = false;
@@ -272,7 +322,7 @@ static bool drm_fb_helper_force_kernel_mode(void)
        return error;
 }
-int drm_fb_helper_panic(struct notifier_block *n, unsigned long ununsed,
+static int drm_fb_helper_panic(struct notifier_block *n, unsigned long ununsed,
                        void *panic_str)
 {
        /*
@@ -285,26 +335,11 @@ int drm_fb_helper_panic(struct notifier_block *n, unsigned long ununsed,
        pr_err("panic occurred, switching back to text console\n");
        return drm_fb_helper_force_kernel_mode();
 }
-EXPORT_SYMBOL(drm_fb_helper_panic);
 static struct notifier_block paniced = {
        .notifier_call = drm_fb_helper_panic,
 };
-/**
- * drm_fb_helper_restore - restore the framebuffer console (kernel) config
- *
- * Restore's the kernel's fbcon mode, used for lastclose & panic paths.
- */
-void drm_fb_helper_restore(void)
-{
-        bool ret;
-        ret = drm_fb_helper_force_kernel_mode();
-        if (ret == true)
-                DRM_ERROR("Failed to restore crtc configuration\n");
-}
-EXPORT_SYMBOL(drm_fb_helper_restore);
 static bool drm_fb_helper_is_bound(struct drm_fb_helper *fb_helper)
 {
        struct drm_device *dev = fb_helper->dev;
@@ -326,7 +361,10 @@ static bool drm_fb_helper_is_bound(struct drm_fb_helper *fb_helper)
 #ifdef CONFIG_MAGIC_SYSRQ
 static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
 {
-        drm_fb_helper_restore();
+        bool ret;
+        ret = drm_fb_helper_force_kernel_mode();
+        if (ret == true)
+                DRM_ERROR("Failed to restore crtc configuration\n");
 }
 static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
@@ -353,6 +391,14 @@ static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
        int i, j;
        /*
+         * fbdev->blank can be called from irq context in case of a panic.
+         * Since we already have our own special panic handler which will
+         * restore the fbdev console mode completely, just bail out early.
+         */
+        if (oops_in_progress)
+                return;
+        /*
         * For each CRTC in this fb, turn the connectors on/off.
         */
        drm_modeset_lock_all(dev);
@@ -378,6 +424,11 @@ static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
        drm_modeset_unlock_all(dev);
 }
+/**
+ * drm_fb_helper_blank - implementation for ->fb_blank
+ * @blank: desired blanking state
+ * @info: fbdev registered by the helper
+ */
 int drm_fb_helper_blank(int blank, struct fb_info *info)
 {
        switch (blank) {
@@ -421,6 +472,24 @@ static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper)
        kfree(helper->crtc_info);
 }
+/**
+ * drm_fb_helper_init - initialize a drm_fb_helper structure
+ * @dev: drm device
+ * @fb_helper: driver-allocated fbdev helper structure to initialize
+ * @crtc_count: maximum number of crtcs to support in this fbdev emulation
+ * @max_conn_count: max connector count
+ *
+ * This allocates the structures for the fbdev helper with the given limits.
+ * Note that this won't yet touch the hardware (through the driver interfaces)
+ * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
+ * to allow driver writes more control over the exact init sequence.
+ *
+ * Drivers must set fb_helper->funcs before calling
+ * drm_fb_helper_initial_config().
+ *
+ * RETURNS:
+ * Zero if everything went ok, nonzero otherwise.
+ */
 int drm_fb_helper_init(struct drm_device *dev,
                       struct drm_fb_helper *fb_helper,
                       int crtc_count, int max_conn_count)
@@ -549,6 +618,11 @@ static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
        return 0;
 }
+/**
+ * drm_fb_helper_setcmap - implementation for ->fb_setcmap
+ * @cmap: cmap to set
+ * @info: fbdev registered by the helper
+ */
 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
 {
        struct drm_fb_helper *fb_helper = info->par;
@@ -588,6 +662,11 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
 }
 EXPORT_SYMBOL(drm_fb_helper_setcmap);
+/**
+ * drm_fb_helper_check_var - implementation for ->fb_check_var
+ * @var: screeninfo to check
+ * @info: fbdev registered by the helper
+ */
 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
                            struct fb_info *info)
 {
@@ -680,13 +759,19 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
 }
 EXPORT_SYMBOL(drm_fb_helper_check_var);
-/* this will let fbcon do the mode init */
+/**
+ * drm_fb_helper_set_par - implementation for ->fb_set_par
+ * @info: fbdev registered by the helper
+ *
+ * This will let fbcon do the mode init and is called at initialization time by
+ * the fbdev core when registering the driver, and later on through the hotplug
+ * callback.
+ */
 int drm_fb_helper_set_par(struct fb_info *info)
 {
        struct drm_fb_helper *fb_helper = info->par;
        struct drm_device *dev = fb_helper->dev;
        struct fb_var_screeninfo *var = &info->var;
-        struct drm_crtc *crtc;
        int ret;
        int i;
@@ -697,7 +782,6 @@ int drm_fb_helper_set_par(struct fb_info *info)
        drm_modeset_lock_all(dev);
        for (i = 0; i < fb_helper->crtc_count; i++) {
-                crtc = fb_helper->crtc_info[i].mode_set.crtc;
                ret = drm_mode_set_config_internal(&fb_helper->crtc_info[i].mode_set);
                if (ret) {
                        drm_modeset_unlock_all(dev);
@@ -714,6 +798,11 @@ int drm_fb_helper_set_par(struct fb_info *info)
 }
 EXPORT_SYMBOL(drm_fb_helper_set_par);
+/**
+ * drm_fb_helper_pan_display - implementation for ->fb_pan_display
+ * @var: updated screen information
+ * @info: fbdev registered by the helper
+ */
 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
                              struct fb_info *info)
 {
@@ -751,10 +840,15 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
 }
 EXPORT_SYMBOL(drm_fb_helper_pan_display);
-int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
+/*
-                                  int preferred_bpp)
+ * Allocates the backing storage and sets up the fbdev info structure through
+ * the ->fb_probe callback and then registers the fbdev and sets up the panic
+ * notifier.
+ */
+static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
+                                         int preferred_bpp)
 {
-        int new_fb = 0;
+        int ret = 0;
        int crtc_count = 0;
        int i;
        struct fb_info *info;
@@ -832,27 +926,30 @@ int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
        }
        /* push down into drivers */
-        new_fb = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
+        ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
-        if (new_fb < 0)
+        if (ret < 0)
-                return new_fb;
+                return ret;
        info = fb_helper->fbdev;
-        /* set the fb pointer */
+        /*
+         * Set the fb pointer - usually drm_setup_crtcs does this for hotplug
+         * events, but at init time drm_setup_crtcs needs to be called before
+         * the fb is allocated (since we need to figure out the desired size of
+         * the fb before we can allocate it ...). Hence we need to fix things up
+         * here again.
+         */
        for (i = 0; i < fb_helper->crtc_count; i++)
-                fb_helper->crtc_info[i].mode_set.fb = fb_helper->fb;
+                if (fb_helper->crtc_info[i].mode_set.num_connectors)
+                        fb_helper->crtc_info[i].mode_set.fb = fb_helper->fb;
-        if (new_fb) {
-                info->var.pixclock = 0;
-                if (register_framebuffer(info) < 0)
-                        return -EINVAL;
-                dev_info(fb_helper->dev->dev, "fb%d: %s frame buffer device\n",
+        info->var.pixclock = 0;
-                                info->node, info->fix.id);
+        if (register_framebuffer(info) < 0)
+                return -EINVAL;
-        } else {
+        dev_info(fb_helper->dev->dev, "fb%d: %s frame buffer device\n",
-                drm_fb_helper_set_par(info);
+                        info->node, info->fix.id);
-        }
        /* Switch back to kernel console on panic */
        /* multi card linked list maybe */
@@ -862,13 +959,25 @@ int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
                                               &paniced);
                register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
        }
-        if (new_fb)
-                list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
+        list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
        return 0;
 }
-EXPORT_SYMBOL(drm_fb_helper_single_fb_probe);
+/**
+ * drm_fb_helper_fill_fix - initializes fixed fbdev information
+ * @info: fbdev registered by the helper
+ * @pitch: desired pitch
+ * @depth: desired depth
+ *
+ * Helper to fill in the fixed fbdev information useful for a non-accelerated
+ * fbdev emulations. Drivers which support acceleration methods which impose
+ * additional constraints need to set up their own limits.
+ *
+ * Drivers should call this (or their equivalent setup code) from their
+ * ->fb_probe callback.
+ */
 void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
                            uint32_t depth)
 {
@@ -889,6 +998,20 @@ void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
 }
 EXPORT_SYMBOL(drm_fb_helper_fill_fix);
+/**
+ * drm_fb_helper_fill_var - initalizes variable fbdev information
+ * @info: fbdev instance to set up
+ * @fb_helper: fb helper instance to use as template
+ * @fb_width: desired fb width
+ * @fb_height: desired fb height
+ *
+ * Sets up the variable fbdev metainformation from the given fb helper instance
+ * and the drm framebuffer allocated in fb_helper->fb.
+ *
+ * Drivers should call this (or their equivalent setup code) from their
+ * ->fb_probe callback after having allocated the fbdev backing
+ * storage framebuffer.
+ */
 void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
                            uint32_t fb_width, uint32_t fb_height)
 {
@@ -1312,6 +1435,7 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper)
        for (i = 0; i < fb_helper->crtc_count; i++) {
                modeset = &fb_helper->crtc_info[i].mode_set;
                modeset->num_connectors = 0;
+                modeset->fb = NULL;
        }
        for (i = 0; i < fb_helper->connector_count; i++) {
@@ -1328,9 +1452,21 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper)
                        modeset->mode = drm_mode_duplicate(dev,
                                                           fb_crtc->desired_mode);
                        modeset->connectors[modeset->num_connectors++] = fb_helper->connector_info[i]->connector;
+                        modeset->fb = fb_helper->fb;
                }
        }
+        /* Clear out any old modes if there are no more connected outputs. */
+        for (i = 0; i < fb_helper->crtc_count; i++) {
+                modeset = &fb_helper->crtc_info[i].mode_set;
+                if (modeset->num_connectors == 0) {
+                        BUG_ON(modeset->fb);
+                        BUG_ON(modeset->num_connectors);
+                        if (modeset->mode)
+                                drm_mode_destroy(dev, modeset->mode);
+                        modeset->mode = NULL;
+                }
+        }
 out:
        kfree(crtcs);
        kfree(modes);
@@ -1338,18 +1474,23 @@ out:
 }
 /**
- * drm_helper_initial_config - setup a sane initial connector configuration
+ * drm_fb_helper_initial_config - setup a sane initial connector configuration
 * @fb_helper: fb_helper device struct
 * @bpp_sel: bpp value to use for the framebuffer configuration
 *
- * LOCKING:
- * Called at init time by the driver to set up the @fb_helper initial
- * configuration, must take the mode config lock.
- *
 * Scans the CRTCs and connectors and tries to put together an initial setup.
 * At the moment, this is a cloned configuration across all heads with
 * a new framebuffer object as the backing store.
 *
+ * Note that this also registers the fbdev and so allows userspace to call into
+ * the driver through the fbdev interfaces.
+ *
+ * This function will call down into the ->fb_probe callback to let
+ * the driver allocate and initialize the fbdev info structure and the drm
+ * framebuffer used to back the fbdev. drm_fb_helper_fill_var() and
+ * drm_fb_helper_fill_fix() are provided as helpers to setup simple default
+ * values for the fbdev info structure.
+ *
 * RETURNS:
 * Zero if everything went ok, nonzero otherwise.
 */
@@ -1358,9 +1499,6 @@ bool drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
        struct drm_device *dev = fb_helper->dev;
        int count = 0;
-        /* disable all the possible outputs/crtcs before entering KMS mode */
-        drm_helper_disable_unused_functions(fb_helper->dev);
        drm_fb_helper_parse_command_line(fb_helper);
        count = drm_fb_helper_probe_connector_modes(fb_helper,
@@ -1383,12 +1521,17 @@ EXPORT_SYMBOL(drm_fb_helper_initial_config);
 *                               probing all the outputs attached to the fb
 * @fb_helper: the drm_fb_helper
 *
- * LOCKING:
- * Called at runtime, must take mode config lock.
- *
 * Scan the connectors attached to the fb_helper and try to put together a
 * setup after *notification of a change in output configuration.
 *
+ * Called at runtime, takes the mode config locks to be able to check/change the
+ * modeset configuration. Must be run from process context (which usually means
+ * either the output polling work or a work item launched from the driver's
+ * hotplug interrupt).
+ *
+ * Note that the driver must ensure that this is only called _after_ the fb has
+ * been fully set up, i.e. after the call to drm_fb_helper_initial_config.
+ *
 * RETURNS:
 * 0 on success and a non-zero error code otherwise.
 */
@@ -1418,7 +1561,9 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
        drm_setup_crtcs(fb_helper);
        drm_modeset_unlock_all(dev);
-        return drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
+        drm_fb_helper_set_par(fb_helper->fbdev);
+        return 0;
 }
 EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index 90d335cfb8c0..68f0045f86b8 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -226,36 +226,8 @@ out:
        return ret;
 }
-static int exynos_drm_fbdev_probe(struct drm_fb_helper *helper,
-                                   struct drm_fb_helper_surface_size *sizes)
-{
-        int ret = 0;
-        DRM_DEBUG_KMS("%s\n", __FILE__);
-        /*
-         * with !helper->fb, it means that this funcion is called first time
-         * and after that, the helper->fb would be used as clone mode.
-         */
-        if (!helper->fb) {
-                ret = exynos_drm_fbdev_create(helper, sizes);
-                if (ret < 0) {
-                        DRM_ERROR("failed to create fbdev.\n");
-                        return ret;
-                }
-                /*
-                 * fb_helper expects a value more than 1 if succeed
-                 * because register_framebuffer() should be called.
-                 */
-                ret = 1;
-        }
-        return ret;
-}
 static struct drm_fb_helper_funcs exynos_drm_fb_helper_funcs = {
-        .fb_probe =     exynos_drm_fbdev_probe,
+        .fb_probe =     exynos_drm_fbdev_create,
 };
 int exynos_drm_fbdev_init(struct drm_device *dev)
@@ -295,6 +267,9 @@ int exynos_drm_fbdev_init(struct drm_device *dev)
        }
+        /* disable all the possible outputs/crtcs before entering KMS mode */
+        drm_helper_disable_unused_functions(dev);
        ret = drm_fb_helper_initial_config(helper, PREFERRED_BPP);
        if (ret < 0) {
                DRM_ERROR("failed to set up hw configuration.\n");
@@ -376,5 +351,7 @@ void exynos_drm_fbdev_restore_mode(struct drm_device *dev)
        if (!private || !private->fb_helper)
                return;
+        drm_modeset_lock_all(dev);
        drm_fb_helper_restore_fbdev_mode(private->fb_helper);
+        drm_modeset_unlock_all(dev);
 }
diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c
index c1ef37e2efdf..2590cac84257 100644
--- a/drivers/gpu/drm/gma500/framebuffer.c
+++ b/drivers/gpu/drm/gma500/framebuffer.c
@@ -545,9 +545,7 @@ static int psbfb_probe(struct drm_fb_helper *helper,
        struct psb_fbdev *psb_fbdev = (struct psb_fbdev *)helper;
        struct drm_device *dev = psb_fbdev->psb_fb_helper.dev;
        struct drm_psb_private *dev_priv = dev->dev_private;
-        int new_fb = 0;
        int bytespp;
-        int ret;
        bytespp = sizes->surface_bpp / 8;
        if (bytespp == 3)       /* no 24bit packed */
@@ -562,13 +560,7 @@ static int psbfb_probe(struct drm_fb_helper *helper,
                sizes->surface_depth = 16;
        }
-        if (!helper->fb) {
+        return psbfb_create(psb_fbdev, sizes);
-                ret = psbfb_create(psb_fbdev, sizes);
-                if (ret)
-                        return ret;
-                new_fb = 1;
-        }
-        return new_fb;
 }
 static struct drm_fb_helper_funcs psb_fb_helper_funcs = {
@@ -616,6 +608,10 @@ int psb_fbdev_init(struct drm_device *dev)
                                                        INTELFB_CONN_LIMIT);
        drm_fb_helper_single_add_all_connectors(&fbdev->psb_fb_helper);
+        /* disable all the possible outputs/crtcs before entering KMS mode */
+        drm_helper_disable_unused_functions(dev);
        drm_fb_helper_initial_config(&fbdev->psb_fb_helper, 32);
        return 0;
 }
diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index 68e79f32e100..729dd1a3fe72 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -685,7 +685,6 @@ static void intel_crt_reset(struct drm_connector *connector)
 static const struct drm_encoder_helper_funcs crt_encoder_funcs = {
        .mode_fixup = intel_crt_mode_fixup,
        .mode_set = intel_crt_mode_set,
-        .disable = intel_encoder_noop,
 };
 static const struct drm_connector_funcs intel_crt_connector_funcs = {
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index cedf4ab5ff16..a259e09eb6a8 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1481,7 +1481,6 @@ static const struct drm_encoder_funcs intel_ddi_funcs = {
 static const struct drm_encoder_helper_funcs intel_ddi_helper_funcs = {
        .mode_fixup = intel_ddi_mode_fixup,
        .mode_set = intel_ddi_mode_set,
-        .disable = intel_encoder_noop,
 };
 void intel_ddi_init(struct drm_device *dev, enum port port)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 0dfecaf599ff..ca8d5929063e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3718,10 +3718,6 @@ void intel_crtc_update_dpms(struct drm_crtc *crtc)
        intel_crtc_update_sarea(crtc, enable);
 }
-static void intel_crtc_noop(struct drm_crtc *crtc)
-{
-}
 static void intel_crtc_disable(struct drm_crtc *crtc)
 {
        struct drm_device *dev = crtc->dev;
@@ -3770,10 +3766,6 @@ void intel_modeset_disable(struct drm_device *dev)
        }
 }
-void intel_encoder_noop(struct drm_encoder *encoder)
-{
-}
 void intel_encoder_destroy(struct drm_encoder *encoder)
 {
        struct intel_encoder *intel_encoder = to_intel_encoder(encoder);
@@ -7277,7 +7269,6 @@ free_work:
 static struct drm_crtc_helper_funcs intel_helper_funcs = {
        .mode_set_base_atomic = intel_pipe_set_base_atomic,
        .load_lut = intel_crtc_load_lut,
-        .disable = intel_crtc_noop,
 };
 bool intel_encoder_check_is_cloned(struct intel_encoder *encoder)
@@ -7987,14 +7978,9 @@ static int intel_crtc_set_config(struct drm_mode_set *set)
        BUG_ON(!set->crtc);
        BUG_ON(!set->crtc->helper_private);
-        if (!set->mode)
+        /* Enforce sane interface api - has been abused by the fb helper. */
-                set->fb = NULL;
+        BUG_ON(!set->mode && set->fb);
+        BUG_ON(set->fb && set->num_connectors == 0);
-        /* The fb helper likes to play gross jokes with ->mode_set_config.
-         * Unfortunately the crtc helper doesn't do much at all for this case,
-         * so we have to cope with this madness until the fb helper is fixed up. */
-        if (set->fb && set->num_connectors == 0)
-                return 0;
        if (set->fb) {
                DRM_DEBUG_KMS("[CRTC:%d] [FB:%d] #connectors=%d (x y) (%i %i)\n",
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 56e408b2e3c8..13c1536a8bb2 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -2561,7 +2561,6 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder)
 static const struct drm_encoder_helper_funcs intel_dp_helper_funcs = {
        .mode_fixup = intel_dp_mode_fixup,
        .mode_set = intel_dp_mode_set,
-        .disable = intel_encoder_noop,
 };
 static const struct drm_connector_funcs intel_dp_connector_funcs = {
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 13afb37d8dec..a2ec01c49f40 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -521,7 +521,6 @@ extern void intel_modeset_disable(struct drm_device *dev);
 extern void intel_crtc_restore_mode(struct drm_crtc *crtc);
 extern void intel_crtc_load_lut(struct drm_crtc *crtc);
 extern void intel_crtc_update_dpms(struct drm_crtc *crtc);
-extern void intel_encoder_noop(struct drm_encoder *encoder);
 extern void intel_encoder_destroy(struct drm_encoder *encoder);
 extern void intel_encoder_dpms(struct intel_encoder *encoder, int mode);
 extern bool intel_encoder_check_is_cloned(struct intel_encoder *encoder);
diff --git a/drivers/gpu/drm/i915/intel_dvo.c b/drivers/gpu/drm/i915/intel_dvo.c
index 15da99533e5b..00e70dbe82da 100644
--- a/drivers/gpu/drm/i915/intel_dvo.c
+++ b/drivers/gpu/drm/i915/intel_dvo.c
@@ -345,7 +345,6 @@ static void intel_dvo_destroy(struct drm_connector *connector)
 static const struct drm_encoder_helper_funcs intel_dvo_helper_funcs = {
        .mode_fixup = intel_dvo_mode_fixup,
        .mode_set = intel_dvo_mode_set,
-        .disable = intel_encoder_noop,
 };
 static const struct drm_connector_funcs intel_dvo_connector_funcs = {
diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index 1c510da04d16..981bdce3634e 100644
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -57,9 +57,10 @@ static struct fb_ops intelfb_ops = {
        .fb_debug_leave = drm_fb_helper_debug_leave,
 };
-static int intelfb_create(struct intel_fbdev *ifbdev,
+static int intelfb_create(struct drm_fb_helper *helper,
                          struct drm_fb_helper_surface_size *sizes)
 {
+        struct intel_fbdev *ifbdev = (struct intel_fbdev *)helper;
        struct drm_device *dev = ifbdev->helper.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct fb_info *info;
@@ -181,26 +182,10 @@ out:
        return ret;
 }
-static int intel_fb_find_or_create_single(struct drm_fb_helper *helper,
-                                          struct drm_fb_helper_surface_size *sizes)
-{
-        struct intel_fbdev *ifbdev = (struct intel_fbdev *)helper;
-        int new_fb = 0;
-        int ret;
-        if (!helper->fb) {
-                ret = intelfb_create(ifbdev, sizes);
-                if (ret)
-                        return ret;
-                new_fb = 1;
-        }
-        return new_fb;
-}
 static struct drm_fb_helper_funcs intel_fb_helper_funcs = {
        .gamma_set = intel_crtc_fb_gamma_set,
        .gamma_get = intel_crtc_fb_gamma_get,
-        .fb_probe = intel_fb_find_or_create_single,
+        .fb_probe = intelfb_create,
 };
 static void intel_fbdev_destroy(struct drm_device *dev,
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 5b4efd64c2f9..3883bed80faa 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -972,7 +972,6 @@ static void intel_hdmi_destroy(struct drm_connector *connector)
 static const struct drm_encoder_helper_funcs intel_hdmi_helper_funcs = {
        .mode_fixup = intel_hdmi_mode_fixup,
        .mode_set = intel_hdmi_mode_set,
-        .disable = intel_encoder_noop,
 };
 static const struct drm_connector_funcs intel_hdmi_connector_funcs = {
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 5e3f08e3fd8b..feb43fd7debf 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -656,7 +656,6 @@ static int intel_lvds_set_property(struct drm_connector *connector,
 static const struct drm_encoder_helper_funcs intel_lvds_helper_funcs = {
        .mode_fixup = intel_lvds_mode_fixup,
        .mode_set = intel_lvds_mode_set,
-        .disable = intel_encoder_noop,
 };
 static const struct drm_connector_helper_funcs intel_lvds_connector_helper_funcs = {
diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index f01063a2323a..33b46d9694ea 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -2043,7 +2043,6 @@ done:
 static const struct drm_encoder_helper_funcs intel_sdvo_helper_funcs = {
        .mode_fixup = intel_sdvo_mode_fixup,
        .mode_set = intel_sdvo_mode_set,
-        .disable = intel_encoder_noop,
 };
 static const struct drm_connector_funcs intel_sdvo_connector_funcs = {
diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c
index 984a113c5d13..d808421c1c80 100644
--- a/drivers/gpu/drm/i915/intel_tv.c
+++ b/drivers/gpu/drm/i915/intel_tv.c
@@ -1487,7 +1487,6 @@ out:
 static const struct drm_encoder_helper_funcs intel_tv_helper_funcs = {
        .mode_fixup = intel_tv_mode_fixup,
        .mode_set = intel_tv_mode_set,
-        .disable = intel_encoder_noop,
 };
 static const struct drm_connector_funcs intel_tv_connector_funcs = {
diff --git a/drivers/gpu/drm/mgag200/mgag200_fb.c b/drivers/gpu/drm/mgag200/mgag200_fb.c
index 5c69b432f99a..d2253f639481 100644
--- a/drivers/gpu/drm/mgag200/mgag200_fb.c
+++ b/drivers/gpu/drm/mgag200/mgag200_fb.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <drm/drmP.h>
 #include <drm/drm_fb_helper.h>
+#include <drm/drm_crtc_helper.h>
 #include <linux/fb.h>
@@ -120,9 +121,10 @@ static int mgag200fb_create_object(struct mga_fbdev *afbdev,
        return ret;
 }
-static int mgag200fb_create(struct mga_fbdev *mfbdev,
+static int mgag200fb_create(struct drm_fb_helper *helper,
                           struct drm_fb_helper_surface_size *sizes)
 {
+        struct mga_fbdev *mfbdev = (struct mga_fbdev *)helper;
        struct drm_device *dev = mfbdev->helper.dev;
        struct drm_mode_fb_cmd2 mode_cmd;
        struct mga_device *mdev = dev->dev_private;
@@ -209,23 +211,6 @@ out:
        return ret;
 }
-static int mga_fb_find_or_create_single(struct drm_fb_helper *helper,
-                                           struct drm_fb_helper_surface_size
-                                           *sizes)
-{
-        struct mga_fbdev *mfbdev = (struct mga_fbdev *)helper;
-        int new_fb = 0;
-        int ret;
-        if (!helper->fb) {
-                ret = mgag200fb_create(mfbdev, sizes);
-                if (ret)
-                        return ret;
-                new_fb = 1;
-        }
-        return new_fb;
-}
 static int mga_fbdev_destroy(struct drm_device *dev,
                                struct mga_fbdev *mfbdev)
 {
@@ -256,7 +241,7 @@ static int mga_fbdev_destroy(struct drm_device *dev,
 static struct drm_fb_helper_funcs mga_fb_helper_funcs = {
        .gamma_set = mga_crtc_fb_gamma_set,
        .gamma_get = mga_crtc_fb_gamma_get,
-        .fb_probe = mga_fb_find_or_create_single,
+        .fb_probe = mgag200fb_create,
 };
 int mgag200_fbdev_init(struct mga_device *mdev)
@@ -278,6 +263,10 @@ int mgag200_fbdev_init(struct mga_device *mdev)
                return ret;
        }
        drm_fb_helper_single_add_all_connectors(&mfbdev->helper);
+        /* disable all the possible outputs/crtcs before entering KMS mode */
+        drm_helper_disable_unused_functions(mdev->dev);
        drm_fb_helper_initial_config(&mfbdev->helper, 32);
        return 0;
diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
index d4ecb4deb484..b03531781580 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
@@ -251,9 +251,10 @@ nouveau_fbcon_zfill(struct drm_device *dev, struct nouveau_fbdev *fbcon)
 }
 static int
-nouveau_fbcon_create(struct nouveau_fbdev *fbcon,
+nouveau_fbcon_create(struct drm_fb_helper *helper,
                     struct drm_fb_helper_surface_size *sizes)
 {
+        struct nouveau_fbdev *fbcon = (struct nouveau_fbdev *)helper;
        struct drm_device *dev = fbcon->dev;
        struct nouveau_drm *drm = nouveau_drm(dev);
        struct nouveau_device *device = nv_device(drm->device);
@@ -388,23 +389,6 @@ out:
        return ret;
 }
-static int
-nouveau_fbcon_find_or_create_single(struct drm_fb_helper *helper,
-                                    struct drm_fb_helper_surface_size *sizes)
-{
-        struct nouveau_fbdev *fbcon = (struct nouveau_fbdev *)helper;
-        int new_fb = 0;
-        int ret;
-        if (!helper->fb) {
-                ret = nouveau_fbcon_create(fbcon, sizes);
-                if (ret)
-                        return ret;
-                new_fb = 1;
-        }
-        return new_fb;
-}
 void
 nouveau_fbcon_output_poll_changed(struct drm_device *dev)
 {
@@ -450,7 +434,7 @@ void nouveau_fbcon_gpu_lockup(struct fb_info *info)
 static struct drm_fb_helper_funcs nouveau_fbcon_helper_funcs = {
        .gamma_set = nouveau_fbcon_gamma_set,
        .gamma_get = nouveau_fbcon_gamma_get,
-        .fb_probe = nouveau_fbcon_find_or_create_single,
+        .fb_probe = nouveau_fbcon_create,
 };
@@ -491,6 +475,9 @@ nouveau_fbcon_init(struct drm_device *dev)
        else
                preferred_bpp = 32;
+        /* disable all the possible outputs/crtcs before entering KMS mode */
+        drm_helper_disable_unused_functions(dev);
        drm_fb_helper_initial_config(&fbcon->helper, preferred_bpp);
        return 0;
 }
diff --git a/drivers/gpu/drm/radeon/radeon_fb.c b/drivers/gpu/drm/radeon/radeon_fb.c
index 515e5ee1f9ee..b1746741bc59 100644
--- a/drivers/gpu/drm/radeon/radeon_fb.c
+++ b/drivers/gpu/drm/radeon/radeon_fb.c
@@ -187,9 +187,10 @@ out_unref:
        return ret;
 }
-static int radeonfb_create(struct radeon_fbdev *rfbdev,
+static int radeonfb_create(struct drm_fb_helper *helper,
                           struct drm_fb_helper_surface_size *sizes)
 {
+        struct radeon_fbdev *rfbdev = (struct radeon_fbdev *)helper;
        struct radeon_device *rdev = rfbdev->rdev;
        struct fb_info *info;
        struct drm_framebuffer *fb = NULL;
@@ -300,22 +301,6 @@ out_unref:
        return ret;
 }
-static int radeon_fb_find_or_create_single(struct drm_fb_helper *helper,
-                                           struct drm_fb_helper_surface_size *sizes)
-{
-        struct radeon_fbdev *rfbdev = (struct radeon_fbdev *)helper;
-        int new_fb = 0;
-        int ret;
-        if (!helper->fb) {
-                ret = radeonfb_create(rfbdev, sizes);
-                if (ret)
-                        return ret;
-                new_fb = 1;
-        }
-        return new_fb;
-}
 void radeon_fb_output_poll_changed(struct radeon_device *rdev)
 {
        drm_fb_helper_hotplug_event(&rdev->mode_info.rfbdev->helper);
@@ -349,7 +334,7 @@ static int radeon_fbdev_destroy(struct drm_device *dev, struct radeon_fbdev *rfb
 static struct drm_fb_helper_funcs radeon_fb_helper_funcs = {
        .gamma_set = radeon_crtc_fb_gamma_set,
        .gamma_get = radeon_crtc_fb_gamma_get,
-        .fb_probe = radeon_fb_find_or_create_single,
+        .fb_probe = radeonfb_create,
 };
 int radeon_fbdev_init(struct radeon_device *rdev)
@@ -379,6 +364,10 @@ int radeon_fbdev_init(struct radeon_device *rdev)
        }
        drm_fb_helper_single_add_all_connectors(&rfbdev->helper);
+        /* disable all the possible outputs/crtcs before entering KMS mode */
+        drm_helper_disable_unused_functions(rdev->ddev);
        drm_fb_helper_initial_config(&rfbdev->helper, bpp_sel);
        return 0;
 }
diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
index 97993c6835fd..03914953cb1c 100644
--- a/drivers/gpu/drm/tegra/fb.c
+++ b/drivers/gpu/drm/tegra/fb.c
@@ -39,10 +39,6 @@ int tegra_drm_fb_init(struct drm_device *drm)
        if (IS_ERR(fbdev))
                return PTR_ERR(fbdev);
-#ifndef CONFIG_FRAMEBUFFER_CONSOLE
-        drm_fbdev_cma_restore_mode(fbdev);
-#endif
        host1x->fbdev = fbdev;
        return 0;
diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c
index b9feec9d08d3..9f4be3d4a02e 100644
--- a/drivers/gpu/drm/udl/udl_fb.c
+++ b/drivers/gpu/drm/udl/udl_fb.c
@@ -476,9 +476,10 @@ udl_framebuffer_init(struct drm_device *dev,
 }
-static int udlfb_create(struct udl_fbdev *ufbdev,
+static int udlfb_create(struct drm_fb_helper *helper,
                        struct drm_fb_helper_surface_size *sizes)
 {
+        struct udl_fbdev *ufbdev = (struct udl_fbdev *)helper;
        struct drm_device *dev = ufbdev->helper.dev;
        struct fb_info *info;
        struct device *device = &dev->usbdev->dev;
@@ -556,27 +557,10 @@ out:
        return ret;
 }
-static int udl_fb_find_or_create_single(struct drm_fb_helper *helper,
-                                        struct drm_fb_helper_surface_size *sizes)
-{
-        struct udl_fbdev *ufbdev = (struct udl_fbdev *)helper;
-        int new_fb = 0;
-        int ret;
-        if (!helper->fb) {
-                ret = udlfb_create(ufbdev, sizes);
-                if (ret)
-                        return ret;
-                new_fb = 1;
-        }
-        return new_fb;
-}
 static struct drm_fb_helper_funcs udl_fb_helper_funcs = {
        .gamma_set = udl_crtc_fb_gamma_set,
        .gamma_get = udl_crtc_fb_gamma_get,
-        .fb_probe = udl_fb_find_or_create_single,
+        .fb_probe = udlfb_create,
 };
 static void udl_fbdev_destroy(struct drm_device *dev,
@@ -619,6 +603,10 @@ int udl_fbdev_init(struct drm_device *dev)
        }
        drm_fb_helper_single_add_all_connectors(&ufbdev->helper);
+        /* disable all the possible outputs/crtcs before entering KMS mode */
+        drm_helper_disable_unused_functions(dev);
        drm_fb_helper_initial_config(&ufbdev->helper, bpp_sel);
        return 0;
 }
diff --git a/drivers/staging/omapdrm/omap_fbdev.c b/drivers/staging/omapdrm/omap_fbdev.c
index 2728e37e02be..caefdf9430f8 100644
--- a/drivers/staging/omapdrm/omap_fbdev.c
+++ b/drivers/staging/omapdrm/omap_fbdev.c
@@ -296,25 +296,10 @@ static void omap_crtc_fb_gamma_get(struct drm_crtc *crtc,
        DBG("fbdev: get gamma");
 }
-static int omap_fbdev_probe(struct drm_fb_helper *helper,
-                struct drm_fb_helper_surface_size *sizes)
-{
-        int new_fb = 0;
-        int ret;
-        if (!helper->fb) {
-                ret = omap_fbdev_create(helper, sizes);
-                if (ret)
-                        return ret;
-                new_fb = 1;
-        }
-        return new_fb;
-}
 static struct drm_fb_helper_funcs omap_fb_helper_funcs = {
        .gamma_set = omap_crtc_fb_gamma_set,
        .gamma_get = omap_crtc_fb_gamma_get,
-        .fb_probe = omap_fbdev_probe,
+        .fb_probe = omap_fbdev_create,
 };
 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
@@ -369,6 +354,10 @@ struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev)
        }
        drm_fb_helper_single_add_all_connectors(helper);
+        /* disable all the possible outputs/crtcs before entering KMS mode */
+        drm_helper_disable_unused_functions(dev);
        drm_fb_helper_initial_config(helper, 32);
        priv->fbdev = helper;
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index e90c8dcc028d..8b7762728639 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -867,6 +867,7 @@ struct drm_prop_enum_list {
 extern void drm_modeset_lock_all(struct drm_device *dev);
 extern void drm_modeset_unlock_all(struct drm_device *dev);
+extern void drm_warn_on_modeset_not_all_locked(struct drm_device *dev);
 extern int drm_crtc_init(struct drm_device *dev,
                         struct drm_crtc *crtc,
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 5120b01c2eeb..c09511625a11 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -48,6 +48,18 @@ struct drm_fb_helper_surface_size {
        u32 surface_depth;
 };
+/**
+ * struct drm_fb_helper_funcs - driver callbacks for the fbdev emulation library
+ * @gamma_set: - Set the given gamma lut register on the given crtc.
+ * @gamma_get: - Read the given gamma lut register on the given crtc, used to
+ *               save the current lut when force-restoring the fbdev for e.g.
+ *               kdbg.
+ * @fb_probe: - Driver callback to allocate and initialize the fbdev info
+ *              structure. Futhermore it also needs to allocate the drm
+ *              framebuffer used to back the fbdev.
+ *
+ * Driver callbacks used by the fbdev emulation helper library.
+ */
 struct drm_fb_helper_funcs {
        void (*gamma_set)(struct drm_crtc *crtc, u16 red, u16 green,
                          u16 blue, int regno);
@@ -65,9 +77,7 @@ struct drm_fb_helper_connector {
 struct drm_fb_helper {
        struct drm_framebuffer *fb;
-        struct drm_framebuffer *saved_fb;
        struct drm_device *dev;
-        struct drm_display_mode *mode;
        int crtc_count;
        struct drm_fb_helper_crtc *crtc_info;
        int connector_count;
@@ -82,9 +92,6 @@ struct drm_fb_helper {
        bool delayed_hotplug;
 };
-int drm_fb_helper_single_fb_probe(struct drm_fb_helper *helper,
-                                  int preferred_bpp);
 int drm_fb_helper_init(struct drm_device *dev,
                       struct drm_fb_helper *helper, int crtc_count,
                       int max_conn);
@@ -103,7 +110,6 @@ int drm_fb_helper_setcolreg(unsigned regno,
                            struct fb_info *info);
 bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper);
-void drm_fb_helper_restore(void);
 void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
                            uint32_t fb_width, uint32_t fb_height);
 void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,