2 files changed, 127 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2cc18e516a2a..ede87aa3b24b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -51,7 +51,10 @@ static void ironlake_pch_clock_get(struct intel_crtc *crtc,
 
 static int intel_set_mode(struct drm_crtc *crtc, struct drm_display_mode *mode,
                           int x, int y, struct drm_framebuffer *old_fb);
-
+static int intel_framebuffer_init(struct drm_device *dev,
+                                  struct intel_framebuffer *ifb,
+                                  struct drm_mode_fb_cmd2 *mode_cmd,
+                                  struct drm_i915_gem_object *obj);
 
 typedef struct {
         int     min, max;
@@ -7692,11 +7695,6 @@ static struct drm_display_mode load_detect_mode = {
                  704, 832, 0, 480, 489, 491, 520, 0, DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC),
 };
 
-static int intel_framebuffer_init(struct drm_device *dev,
-                                  struct intel_framebuffer *ifb,
-                                  struct drm_mode_fb_cmd2 *mode_cmd,
-                                  struct drm_i915_gem_object *obj);
-
 struct drm_framebuffer *
 __intel_framebuffer_create(struct drm_device *dev,
                            struct drm_mode_fb_cmd2 *mode_cmd,
diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index 3a53ee307065..25d2746fe695 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -242,7 +242,130 @@ static void intel_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
         *blue = intel_crtc->lut_b[regno] << 8;
 }
 
+static struct drm_fb_helper_crtc *
+intel_fb_helper_crtc(struct drm_fb_helper *fb_helper, struct drm_crtc *crtc)
+{
+        int i;
+
+        for (i = 0; i < fb_helper->crtc_count; i++)
+                if (fb_helper->crtc_info[i].mode_set.crtc == crtc)
+                        return &fb_helper->crtc_info[i];
+
+        return NULL;
+}
+
+/*
+ * Try to read the BIOS display configuration and use it for the initial
+ * fb configuration.
+ *
+ * The BIOS or boot loader will generally create an initial display
+ * configuration for us that includes some set of active pipes and displays.
+ * This routine tries to figure out which pipes and connectors are active
+ * and stuffs them into the crtcs and modes array given to us by the
+ * drm_fb_helper code.
+ *
+ * The overall sequence is:
+ *   intel_fbdev_init - from driver load
+ *     intel_fbdev_init_bios - initialize the intel_fbdev using BIOS data
+ *     drm_fb_helper_init - build fb helper structs
+ *     drm_fb_helper_single_add_all_connectors - more fb helper structs
+ *   intel_fbdev_initial_config - apply the config
+ *     drm_fb_helper_initial_config - call ->probe then register_framebuffer()
+ *         drm_setup_crtcs - build crtc config for fbdev
+ *           intel_fb_initial_config - find active connectors etc
+ *         drm_fb_helper_single_fb_probe - set up fbdev
+ *           intelfb_create - re-use or alloc fb, build out fbdev structs
+ *
+ * Note that we don't make special consideration whether we could actually
+ * switch to the selected modes without a full modeset. E.g. when the display
+ * is in VGA mode we need to recalculate watermarks and set a new high-res
+ * framebuffer anyway.
+ */
+static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
+                                    struct drm_fb_helper_crtc **crtcs,
+                                    struct drm_display_mode **modes,
+                                    bool *enabled, int width, int height)
+{
+        int i, j;
+
+        for (i = 0; i < fb_helper->connector_count; i++) {
+                struct drm_fb_helper_connector *fb_conn;
+                struct drm_connector *connector;
+                struct drm_encoder *encoder;
+                struct drm_fb_helper_crtc *new_crtc;
+
+                fb_conn = fb_helper->connector_info[i];
+                connector = fb_conn->connector;
+                if (!enabled[i]) {
+                        DRM_DEBUG_KMS("connector %d not enabled, skipping\n",
+                                      connector->base.id);
+                        continue;
+                }
+
+                encoder = connector->encoder;
+                if (!encoder || WARN_ON(!encoder->crtc)) {
+                        DRM_DEBUG_KMS("connector %d has no encoder or crtc, skipping\n",
+                                      connector->base.id);
+                        enabled[i] = false;
+                        continue;
+                }
+
+                new_crtc = intel_fb_helper_crtc(fb_helper, encoder->crtc);
+
+                /*
+                 * Make sure we're not trying to drive multiple connectors
+                 * with a single CRTC, since our cloning support may not
+                 * match the BIOS.
+                 */
+                for (j = 0; j < fb_helper->connector_count; j++) {
+                        if (crtcs[j] == new_crtc)
+                                return false;
+                }
+
+                DRM_DEBUG_KMS("looking for cmdline mode on connector %d\n",
+                              fb_conn->connector->base.id);
+
+                /* go for command line mode first */
+                modes[i] = drm_pick_cmdline_mode(fb_conn, width, height);
+
+                /* try for preferred next */
+                if (!modes[i]) {
+                        DRM_DEBUG_KMS("looking for preferred mode on connector %d\n",
+                                      fb_conn->connector->base.id);
+                        modes[i] = drm_has_preferred_mode(fb_conn, width,
+                                                          height);
+                }
+
+                /* last resort: use current mode */
+                if (!modes[i]) {
+                        /*
+                         * IMPORTANT: We want to use the adjusted mode (i.e.
+                         * after the panel fitter upscaling) as the initial
+                         * config, not the input mode, which is what crtc->mode
+                         * usually contains. But since our current fastboot
+                         * code puts a mode derived from the post-pfit timings
+                         * into crtc->mode this works out correctly. We don't
+                         * use hwmode anywhere right now, so use it for this
+                         * since the fb helper layer wants a pointer to
+                         * something we own.
+                         */
+                        intel_mode_from_pipe_config(&encoder->crtc->hwmode,
+                                                    &to_intel_crtc(encoder->crtc)->config);
+                        modes[i] = &encoder->crtc->hwmode;
+                }
+                crtcs[i] = new_crtc;
+
+                DRM_DEBUG_KMS("connector %s on crtc %d: %s\n",
+                              drm_get_connector_name(connector),
+                              encoder->crtc->base.id,
+                              modes[i]->name);
+        }
+
+        return true;
+}
+
 static struct drm_fb_helper_funcs intel_fb_helper_funcs = {
+        .initial_config = intel_fb_initial_config,
         .gamma_set = intel_crtc_fb_gamma_set,
         .gamma_get = intel_crtc_fb_gamma_get,
         .fb_probe = intelfb_create,