Add tagr drm patchez

1 files changed, 143 insertions, 0 deletions

diff --git a/linux-arm-tagr-01_04-drm_fb-helper.patch b/linux-arm-tagr-01_04-drm_fb-helper.patch
new file mode 100644
index 00000000..4f882e9d
--- /dev/null
+++ b/linux-arm-tagr-01_04-drm_fb-helper.patch
@@ -0,0 +1,143 @@
+From: Daniel Vetter <daniel.vetter@ffwll.ch>
+
+Some drivers need to be able to have a perfect race-free fbcon setup.
+Current drivers only enable hotplug processing after the call to
+drm_fb_helper_initial_config which leaves a tiny but important race.
+
+This race is especially noticable on embedded platforms where the
+driver itself enables the voltage for the hdmi output, since only then
+will monitors (after a bit of delay, as usual) respond by asserting
+the hpd pin.
+
+Most of the infrastructure is already there with the split-out
+drm_fb_helper_init. And drm_fb_helper_initial_config already has all
+the required locking to handle concurrent hpd events since
+
+commit 53f1904bced78d7c00f5d874c662ec3ac85d0f9f
+Author: Daniel Vetter <daniel.vetter@ffwll.ch>
+Date:   Thu Mar 20 14:26:35 2014 +0100
+
+    drm/fb-helper: improve drm_fb_helper_initial_config locking
+
+The only missing bit is making drm_fb_helper_hotplug_event save
+against concurrent calls of drm_fb_helper_initial_config. The only
+unprotected bit is the check for fb_helper->fb.
+
+With that drivers can first initialize the fb helper, then enabel
+hotplug processing and then set up the initial config all in a
+completely race-free manner. Update kerneldoc and convert i915 as a
+proof of concept.
+
+Feature requested by Thierry since his tegra driver atm reliably boots
+slowly enough to misses the hotplug event for an external hdmi screen,
+but also reliably boots to quickly for the hpd pin to be asserted when
+the fb helper calls into the hdmi ->detect function.
+
+Cc: Thierry Reding <treding@nvidia.com>
+Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
+Signed-off-by: Thierry Reding <treding@nvidia.com>
+---
+Changes in v3:
+- remove an additional occurrence of i915's enable_hotplug_processing
+  that was introduced after the original patch
+
+ drivers/gpu/drm/drm_fb_helper.c | 11 +++++------
+ drivers/gpu/drm/i915/i915_dma.c |  3 ---
+ drivers/gpu/drm/i915/i915_drv.c |  2 --
+ drivers/gpu/drm/i915/i915_drv.h |  1 -
+ drivers/gpu/drm/i915/i915_irq.c |  4 ----
+ 5 files changed, 5 insertions(+), 16 deletions(-)
+
+diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
+index d5d8cea1a679..13a098c9af31 100644
+--- a/drivers/gpu/drm/drm_fb_helper.c
++++ b/drivers/gpu/drm/drm_fb_helper.c
+@@ -1613,8 +1613,10 @@ EXPORT_SYMBOL(drm_fb_helper_initial_config);
+  * 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.
++ * Note that drivers may call this even before calling
++ * drm_fb_helper_initial_config but only aftert drm_fb_helper_init. This allows
++ * for a race-free fbcon setup and will make sure that the fbdev emulation will
++ * not miss any hotplug events.
+  *
+  * RETURNS:
+  * 0 on success and a non-zero error code otherwise.
+@@ -1624,11 +1626,8 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
+ 	struct drm_device *dev = fb_helper->dev;
+ 	u32 max_width, max_height;
+ 
+-	if (!fb_helper->fb)
+-		return 0;
+-
+ 	mutex_lock(&fb_helper->dev->mode_config.mutex);
+-	if (!drm_fb_helper_is_bound(fb_helper)) {
++	if (!fb_helper->fb || !drm_fb_helper_is_bound(fb_helper)) {
+ 		fb_helper->delayed_hotplug = true;
+ 		mutex_unlock(&fb_helper->dev->mode_config.mutex);
+ 		return 0;
+diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
+index 5e583a1838f8..84b55665bd87 100644
+--- a/drivers/gpu/drm/i915/i915_dma.c
++++ b/drivers/gpu/drm/i915/i915_dma.c
+@@ -1377,9 +1377,6 @@ static int i915_load_modeset_init(struct drm_device *dev)
+ 	 */
+ 	intel_fbdev_initial_config(dev);
+ 
+-	/* Only enable hotplug handling once the fbdev is fully set up. */
+-	dev_priv->enable_hotplug_processing = true;
+-
+ 	drm_kms_helper_poll_init(dev);
+ 
+ 	return 0;
+diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
+index 6eb45ac7a7d5..b0955fffca98 100644
+--- a/drivers/gpu/drm/i915/i915_drv.c
++++ b/drivers/gpu/drm/i915/i915_drv.c
+@@ -521,7 +521,6 @@ static int i915_drm_freeze(struct drm_device *dev)
+ 		}
+ 
+ 		intel_runtime_pm_disable_interrupts(dev);
+-		dev_priv->enable_hotplug_processing = false;
+ 
+ 		intel_suspend_gt_powersave(dev);
+ 
+@@ -659,7 +658,6 @@ static int __i915_drm_thaw(struct drm_device *dev, bool restore_gtt_mappings)
+ 		 * notifications.
+ 		 * */
+ 		intel_hpd_init(dev);
+-		dev_priv->enable_hotplug_processing = true;
+ 		/* Config may have changed between suspend and resume */
+ 		drm_helper_hpd_irq_event(dev);
+ 	}
+diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
+index 8cea59649ef2..df6a98cd702f 100644
+--- a/drivers/gpu/drm/i915/i915_drv.h
++++ b/drivers/gpu/drm/i915/i915_drv.h
+@@ -1404,7 +1404,6 @@ struct drm_i915_private {
+ 	u32 pipestat_irq_mask[I915_MAX_PIPES];
+ 
+ 	struct work_struct hotplug_work;
+-	bool enable_hotplug_processing;
+ 	struct {
+ 		unsigned long hpd_last_jiffies;
+ 		int hpd_cnt;
+diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
+index 1c1ec22bc7ef..c0d7674c45cd 100644
+--- a/drivers/gpu/drm/i915/i915_irq.c
++++ b/drivers/gpu/drm/i915/i915_irq.c
+@@ -1109,10 +1109,6 @@ static void i915_hotplug_work_func(struct work_struct *work)
+ 	bool changed = false;
+ 	u32 hpd_event_bits;
+ 
+-	/* HPD irq before everything is fully set up. */
+-	if (!dev_priv->enable_hotplug_processing)
+-		return;
+-
+ 	mutex_lock(&mode_config->mutex);
+ 	DRM_DEBUG_KMS("running encoder hotplug functions\n");
+ 
+-- 
+2.0.0