[Intel-gfx] [PATCH] drm/i915: fix kernelfb mode

[Jesse Barnes]

The kernelfb_mode struct isn't correct for multi-CRTC configurations or
configurations where CRTC 2 isn't enabled.  Fix that up for both the
shared fb and per-CRTC fb cases so that panic & sysrq work as expected.

Tested-by: Jason Wessel <jason.wessel at windriver.com>
Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>

diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index 1d30802..042fc29 100644
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -52,6 +52,17 @@ struct intelfb_par {
 	uint32_t crtc_ids[2];
 };
 
+/*
+ * Track each CRTCs intelfb  mode config for restoration at panic or
+ * sysrq time.
+ */
+struct intelfb_console_restore {
+	struct drm_mode_set mode_sets[I915_NUM_PIPE];
+	int num_crtcs;
+};
+
+static struct intelfb_console_restore console_restore;
+
 static int intelfb_setcolreg(unsigned regno, unsigned red, unsigned green,
 			unsigned blue, unsigned transp,
 			struct fb_info *info)
@@ -412,21 +423,6 @@ int intelfb_resize(struct drm_device *dev, struct drm_crtc *crtc)
 }
 EXPORT_SYMBOL(intelfb_resize);
 
-static struct drm_mode_set kernelfb_mode;
-
-static int intelfb_panic(struct notifier_block *n, unsigned long ununsed,
-			 void *panic_str)
-{
-	DRM_ERROR("panic occurred, switching back to text console\n");
-
-	intelfb_restore();
-	return 0;
-}
-
-static struct notifier_block paniced = {
-	.notifier_call = intelfb_panic,
-};
-
 static int intelfb_create(struct drm_device *dev, uint32_t fb_width,
 			  uint32_t fb_height, uint32_t surface_width,
 			  uint32_t surface_height,
@@ -625,7 +621,9 @@ out:
 	return ret;
 }
 
-static int intelfb_multi_fb_probe_crtc(struct drm_device *dev, struct drm_crtc *crtc)
+static int intelfb_multi_fb_probe_crtc(struct drm_device *dev,
+				       struct drm_crtc *crtc,
+				       struct drm_mode_set *set)
 {
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	struct intel_framebuffer *intel_fb;
@@ -701,10 +699,7 @@ static int intelfb_multi_fb_probe_crtc(struct drm_device *dev, struct drm_crtc *
 	DRM_INFO("fb%d: %s frame buffer device\n", info->node,
 	       info->fix.id);
 
-	/* Switch back to kernel console on panic */
-	kernelfb_mode = *modeset;
-	atomic_notifier_chain_register(&panic_notifier_list, &paniced);
-	DRM_DEBUG("registered panic notifier\n");
+	*set = *modeset;
 
 	return 0;
 }
@@ -713,12 +708,15 @@ static int intelfb_multi_fb_probe(struct drm_device *dev)
 {
 
 	struct drm_crtc *crtc;
-	int ret = 0;
+	int ret = 0, crtc_count = 0;
 
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
-		ret = intelfb_multi_fb_probe_crtc(dev, crtc);
+		struct drm_mode_set *set =
+			&console_restore.mode_sets[crtc_count++];
+		ret = intelfb_multi_fb_probe_crtc(dev, crtc, set);
 		if (ret)
 			return ret;
+		console_restore.num_crtcs++;
 	}
 	return ret;
 }
@@ -812,7 +810,12 @@ static int intelfb_single_fb_probe(struct drm_device *dev)
 	 * set configuration.
 	 */
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
-		struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+		struct intel_crtc *intel_crtc;
+
+		if (!drm_helper_crtc_in_use(crtc) || !crtc->desired_mode)
+			continue;
+
+		intel_crtc = to_intel_crtc(crtc);
 
 		modeset = &intel_crtc->mode_set;
 		modeset->fb = &intel_fb->base;
@@ -833,7 +836,7 @@ static int intelfb_single_fb_probe(struct drm_device *dev)
 		for (i = conn_count; i < INTELFB_CONN_LIMIT; i++)
 			modeset->connectors[i] = NULL;
 
-		par->crtc_ids[crtc_count++] = crtc->base.id;
+		par->crtc_ids[crtc_count] = crtc->base.id;
 
 		modeset->num_connectors = conn_count;
 		if (modeset->crtc->desired_mode) {
@@ -842,6 +845,10 @@ static int intelfb_single_fb_probe(struct drm_device *dev)
 			modeset->mode = drm_mode_duplicate(dev,
 							   modeset->crtc->desired_mode);
 		}
+
+		console_restore.mode_sets[crtc_count] = *modeset;
+		console_restore.num_crtcs++;
+		crtc_count++;
 	}
 	par->crtc_count = crtc_count;
 
@@ -855,11 +862,6 @@ static int intelfb_single_fb_probe(struct drm_device *dev)
 	DRM_INFO("fb%d: %s frame buffer device\n", info->node,
 	       info->fix.id);
 
-	/* Switch back to kernel console on panic */
-	kernelfb_mode = *modeset;
-	atomic_notifier_chain_register(&panic_notifier_list, &paniced);
-	DRM_DEBUG("registered panic notifier\n");
-
 	return 0;
 }
 
@@ -870,13 +872,30 @@ static int intelfb_single_fb_probe(struct drm_device *dev)
  */
 void intelfb_restore(void)
 {
-	int ret;
-	if ((ret = drm_crtc_helper_set_config(&kernelfb_mode)) != 0) {
-		DRM_ERROR("Failed to restore crtc configuration: %d\n",
-			  ret);
+	int ret, i;
+
+	for (i = 0; i < console_restore.num_crtcs; i++) {
+		struct drm_mode_set *set = &console_restore.mode_sets[i];
+		if ((ret = drm_crtc_helper_set_config(set)) != 0) {
+			DRM_ERROR("Failed to restore crtc configuration: %d\n",
+				  ret);
+		}
 	}
 }
 
+static int intelfb_panic(struct notifier_block *n, unsigned long ununsed,
+			 void *panic_str)
+{
+	DRM_ERROR("panic occurred, switching back to text console\n");
+
+	intelfb_restore();
+	return 0;
+}
+
+static struct notifier_block paniced = {
+	.notifier_call = intelfb_panic,
+};
+
 static void intelfb_restore_work_fn(struct work_struct *ignored)
 {
 	intelfb_restore();
@@ -924,6 +943,7 @@ int intelfb_probe(struct drm_device *dev)
 		ret = intelfb_single_fb_probe(dev);
 	}
 
+	atomic_notifier_chain_register(&panic_notifier_list, &paniced);
 	register_sysrq_key('v', &sysrq_intelfb_restore_op);
 
 	return ret;
@@ -946,7 +966,7 @@ int intelfb_remove(struct drm_device *dev, struct drm_framebuffer *fb)
 	}
 
 	atomic_notifier_chain_unregister(&panic_notifier_list, &paniced);
-	memset(&kernelfb_mode, 0, sizeof(struct drm_mode_set));
+	memset(&console_restore, 0, sizeof(struct intelfb_console_restore));
 	return 0;
 }
 EXPORT_SYMBOL(intelfb_remove);