Merge branch 'fbcon-locking-fixes' of ssh://people.freedesktop.org/~airlied/linux into drm-next

This pulls in most of Linus tree up to -rc6, this fixes the worst lockdep
reported issues and re-enables fbcon lockdep.

(not the fbcon maintainer)
* 'fbcon-locking-fixes' of ssh://people.freedesktop.org/~airlied/linux: (529 commits)
  Revert "Revert "console: implement lockdep support for console_lock""
  fbcon: fix locking harder
  fb: Yet another band-aid for fixing lockdep mess
  fb: rework locking to fix lock ordering on takeover

4 files changed, 61 insertions, 10 deletions

diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index fdefa8fd72c4..2e2d959acae6 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -529,6 +529,33 @@ static int search_for_mapped_con(void)
         return retval;
 }
 
+static int do_fbcon_takeover(int show_logo)
+{
+        int err, i;
+
+        if (!num_registered_fb)
+                return -ENODEV;
+
+        if (!show_logo)
+                logo_shown = FBCON_LOGO_DONTSHOW;
+
+        for (i = first_fb_vc; i <= last_fb_vc; i++)
+                con2fb_map[i] = info_idx;
+
+        err = do_take_over_console(&fb_con, first_fb_vc, last_fb_vc,
+                                fbcon_is_default);
+
+        if (err) {
+                for (i = first_fb_vc; i <= last_fb_vc; i++)
+                        con2fb_map[i] = -1;
+                info_idx = -1;
+        } else {
+                fbcon_has_console_bind = 1;
+        }
+
+        return err;
+}
+
 static int fbcon_takeover(int show_logo)
 {
         int err, i;
@@ -815,6 +842,8 @@ static void con2fb_init_display(struct vc_data *vc, struct fb_info *info,
  *
  *      Maps a virtual console @unit to a frame buffer device
  *      @newidx.
+ *
+ *      This should be called with the console lock held.
  */
 static int set_con2fb_map(int unit, int newidx, int user)
 {
@@ -832,7 +861,7 @@ static int set_con2fb_map(int unit, int newidx, int user)
 
         if (!search_for_mapped_con() || !con_is_bound(&fb_con)) {
                 info_idx = newidx;
-                return fbcon_takeover(0);
+                return do_fbcon_takeover(0);
         }
 
         if (oldidx != -1)
@@ -840,7 +869,6 @@ static int set_con2fb_map(int unit, int newidx, int user)
 
         found = search_fb_in_map(newidx);
 
-        console_lock();
         con2fb_map[unit] = newidx;
         if (!err && !found)
                 err = con2fb_acquire_newinfo(vc, info, unit, oldidx);
@@ -867,7 +895,6 @@ static int set_con2fb_map(int unit, int newidx, int user)
         if (!search_fb_in_map(info_idx))
                 info_idx = newidx;
 
-        console_unlock();
         return err;
 }
 
@@ -2977,7 +3004,7 @@ static int fbcon_unbind(void)
 {
         int ret;
 
-        ret = unbind_con_driver(&fb_con, first_fb_vc, last_fb_vc,
+        ret = do_unbind_con_driver(&fb_con, first_fb_vc, last_fb_vc,
                                 fbcon_is_default);
 
         if (!ret)
@@ -2992,6 +3019,7 @@ static inline int fbcon_unbind(void)
 }
 #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
 
+/* called with console_lock held */
 static int fbcon_fb_unbind(int idx)
 {
         int i, new_idx = -1, ret = 0;
@@ -3018,6 +3046,7 @@ static int fbcon_fb_unbind(int idx)
         return ret;
 }
 
+/* called with console_lock held */
 static int fbcon_fb_unregistered(struct fb_info *info)
 {
         int i, idx;
@@ -3050,11 +3079,12 @@ static int fbcon_fb_unregistered(struct fb_info *info)
                 primary_device = -1;
 
         if (!num_registered_fb)
-                unregister_con_driver(&fb_con);
+                do_unregister_con_driver(&fb_con);
 
         return 0;
 }
 
+/* called with console_lock held */
 static void fbcon_remap_all(int idx)
 {
         int i;
@@ -3099,6 +3129,7 @@ static inline void fbcon_select_primary(struct fb_info *info)
 }
 #endif /* CONFIG_FRAMEBUFFER_DETECT_PRIMARY */
 
+/* called with console_lock held */
 static int fbcon_fb_registered(struct fb_info *info)
 {
         int ret = 0, i, idx;
@@ -3115,7 +3146,7 @@ static int fbcon_fb_registered(struct fb_info *info)
                 }
 
                 if (info_idx != -1)
-                        ret = fbcon_takeover(1);
+                        ret = do_fbcon_takeover(1);
         } else {
                 for (i = first_fb_vc; i <= last_fb_vc; i++) {
                         if (con2fb_map_boot[i] == idx)
@@ -3251,6 +3282,7 @@ static int fbcon_event_notify(struct notifier_block *self,
                 ret = fbcon_fb_unregistered(info);
                 break;
         case FB_EVENT_SET_CONSOLE_MAP:
+                /* called with console lock held */
                 con2fb = event->data;
                 ret = set_con2fb_map(con2fb->console - 1,
                                      con2fb->framebuffer, 1);
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index 3ff0105a496a..dc61c12ecf8c 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1177,8 +1177,10 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
                 event.data = &con2fb;
                 if (!lock_fb_info(info))
                         return -ENODEV;
+                console_lock();
                 event.info = info;
                 ret = fb_notifier_call_chain(FB_EVENT_SET_CONSOLE_MAP, &event);
+                console_unlock();
                 unlock_fb_info(info);
                 break;
         case FBIOBLANK:
@@ -1650,7 +1652,9 @@ static int do_register_framebuffer(struct fb_info *fb_info)
         event.info = fb_info;
         if (!lock_fb_info(fb_info))
                 return -ENODEV;
+        console_lock();
         fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);
+        console_unlock();
         unlock_fb_info(fb_info);
         return 0;
 }
@@ -1666,8 +1670,10 @@ static int do_unregister_framebuffer(struct fb_info *fb_info)
 
         if (!lock_fb_info(fb_info))
                 return -ENODEV;
+        console_lock();
         event.info = fb_info;
         ret = fb_notifier_call_chain(FB_EVENT_FB_UNBIND, &event);
+        console_unlock();
         unlock_fb_info(fb_info);
 
         if (ret)
@@ -1682,7 +1688,9 @@ static int do_unregister_framebuffer(struct fb_info *fb_info)
         num_registered_fb--;
         fb_cleanup_device(fb_info);
         event.info = fb_info;
+        console_lock();
         fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
+        console_unlock();
 
         /* this may free fb info */
         put_fb_info(fb_info);
@@ -1853,11 +1861,8 @@ int fb_new_modelist(struct fb_info *info)
         err = 1;
 
         if (!list_empty(&info->modelist)) {
-                if (!lock_fb_info(info))
-                        return -ENODEV;
                 event.info = info;
                 err = fb_notifier_call_chain(FB_EVENT_NEW_MODELIST, &event);
-                unlock_fb_info(info);
         }
 
         return err;
diff --git a/drivers/video/fbsysfs.c b/drivers/video/fbsysfs.c
index a55e3669d135..ef476b02fbe5 100644
--- a/drivers/video/fbsysfs.c
+++ b/drivers/video/fbsysfs.c
@@ -177,6 +177,8 @@ static ssize_t store_modes(struct device *device,
         if (i * sizeof(struct fb_videomode) != count)
                 return -EINVAL;
 
+        if (!lock_fb_info(fb_info))
+                return -ENODEV;
         console_lock();
         list_splice(&fb_info->modelist, &old_list);
         fb_videomode_to_modelist((const struct fb_videomode *)buf, i,
@@ -188,6 +190,7 @@ static ssize_t store_modes(struct device *device,
                 fb_destroy_modelist(&old_list);
 
         console_unlock();
+        unlock_fb_info(fb_info);
 
         return 0;
 }
diff --git a/drivers/video/imxfb.c b/drivers/video/imxfb.c
index 12526787a7c7..0abf2bf20836 100644
--- a/drivers/video/imxfb.c
+++ b/drivers/video/imxfb.c
@@ -139,6 +139,7 @@ struct imxfb_info {
         struct clk              *clk_ahb;
         struct clk              *clk_per;
         enum imxfb_type         devtype;
+        bool                    enabled;
 
         /*
          * These are the addresses we mapped
@@ -536,6 +537,10 @@ static void imxfb_exit_backlight(struct imxfb_info *fbi)
 
 static void imxfb_enable_controller(struct imxfb_info *fbi)
 {
+
+        if (fbi->enabled)
+                return;
+
         pr_debug("Enabling LCD controller\n");
 
         writel(fbi->screen_dma, fbi->regs + LCDC_SSA);
@@ -556,6 +561,7 @@ static void imxfb_enable_controller(struct imxfb_info *fbi)
         clk_prepare_enable(fbi->clk_ipg);
         clk_prepare_enable(fbi->clk_ahb);
         clk_prepare_enable(fbi->clk_per);
+        fbi->enabled = true;
 
         if (fbi->backlight_power)
                 fbi->backlight_power(1);
@@ -565,6 +571,9 @@ static void imxfb_enable_controller(struct imxfb_info *fbi)
 
 static void imxfb_disable_controller(struct imxfb_info *fbi)
 {
+        if (!fbi->enabled)
+                return;
+
         pr_debug("Disabling LCD controller\n");
 
         if (fbi->backlight_power)
@@ -575,6 +584,7 @@ static void imxfb_disable_controller(struct imxfb_info *fbi)
         clk_disable_unprepare(fbi->clk_per);
         clk_disable_unprepare(fbi->clk_ipg);
         clk_disable_unprepare(fbi->clk_ahb);
+        fbi->enabled = false;
 
         writel(0, fbi->regs + LCDC_RMCR);
 }
@@ -729,6 +739,8 @@ static int __init imxfb_init_fbinfo(struct platform_device *pdev)
 
         memset(fbi, 0, sizeof(struct imxfb_info));
 
+        fbi->devtype = pdev->id_entry->driver_data;
+
         strlcpy(info->fix.id, IMX_NAME, sizeof(info->fix.id));
 
         info->fix.type                  = FB_TYPE_PACKED_PIXELS;
@@ -789,7 +801,6 @@ static int __init imxfb_probe(struct platform_device *pdev)
                 return -ENOMEM;
 
         fbi = info->par;
-        fbi->devtype = pdev->id_entry->driver_data;
 
         if (!fb_mode)
                 fb_mode = pdata->mode[0].mode.name;