diff mbox

[v2] drm/radeon: Track the status of a page flip more explicitly

Message ID 1404119554-1907-1-git-send-email-michel@daenzer.net (mailing list archive)
State New, archived
Headers show

Commit Message

Michel Dänzer June 30, 2014, 9:12 a.m. UTC 
From: Michel Dänzer <michel.daenzer@amd.com>

This prevents a panic: radeon_crtc_handle_page_flip() could run before
radeon_flip_work_func(), triggering the BUG_ON() in drm_vblank_put().

Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
---

v2: Update log message

 drivers/gpu/drm/radeon/radeon_display.c | 19 ++++++++++++++-----
 drivers/gpu/drm/radeon/radeon_mode.h    |  7 +++++++
 2 files changed, 21 insertions(+), 5 deletions(-)

Comments

Christian König June 30, 2014, 9:14 a.m. UTC | #1 
Am 30.06.2014 11:12, schrieb Michel Dänzer:
> From: Michel Dänzer <michel.daenzer@amd.com>
>
> This prevents a panic: radeon_crtc_handle_page_flip() could run before
> radeon_flip_work_func(), triggering the BUG_ON() in drm_vblank_put().
>
> Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
> Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>
> v2: Update log message
>
>   drivers/gpu/drm/radeon/radeon_display.c | 19 ++++++++++++++-----
>   drivers/gpu/drm/radeon/radeon_mode.h    |  7 +++++++
>   2 files changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
> index 8b575a4..65882cd 100644
> --- a/drivers/gpu/drm/radeon/radeon_display.c
> +++ b/drivers/gpu/drm/radeon/radeon_display.c
> @@ -284,7 +284,6 @@ static void radeon_unpin_work_func(struct work_struct *__work)
>   void radeon_crtc_handle_vblank(struct radeon_device *rdev, int crtc_id)
>   {
>   	struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc_id];
> -	struct radeon_flip_work *work;
>   	unsigned long flags;
>   	u32 update_pending;
>   	int vpos, hpos;
> @@ -294,8 +293,11 @@ void radeon_crtc_handle_vblank(struct radeon_device *rdev, int crtc_id)
>   		return;
>   
>   	spin_lock_irqsave(&rdev->ddev->event_lock, flags);
> -	work = radeon_crtc->flip_work;
> -	if (work == NULL) {
> +	if (radeon_crtc->flip_status != RADEON_FLIP_SUBMITTED) {
> +		DRM_DEBUG_DRIVER("radeon_crtc->flip_status = %d != "
> +				 "RADEON_FLIP_SUBMITTED(%d)\n",
> +				 radeon_crtc->flip_status,
> +				 RADEON_FLIP_SUBMITTED);
>   		spin_unlock_irqrestore(&rdev->ddev->event_lock, flags);
>   		return;
>   	}
> @@ -343,12 +345,17 @@ void radeon_crtc_handle_flip(struct radeon_device *rdev, int crtc_id)
>   
>   	spin_lock_irqsave(&rdev->ddev->event_lock, flags);
>   	work = radeon_crtc->flip_work;
> -	if (work == NULL) {
> +	if (radeon_crtc->flip_status != RADEON_FLIP_SUBMITTED) {
> +		DRM_DEBUG_DRIVER("radeon_crtc->flip_status = %d != "
> +				 "RADEON_FLIP_SUBMITTED(%d)\n",
> +				 radeon_crtc->flip_status,
> +				 RADEON_FLIP_SUBMITTED);
>   		spin_unlock_irqrestore(&rdev->ddev->event_lock, flags);
>   		return;
>   	}
>   
>   	/* Pageflip completed. Clean up. */
> +	radeon_crtc->flip_status = RADEON_FLIP_NONE;
>   	radeon_crtc->flip_work = NULL;
>   
>   	/* wakeup userspace */
> @@ -475,6 +482,7 @@ static void radeon_flip_work_func(struct work_struct *__work)
>   	/* do the flip (mmio) */
>   	radeon_page_flip(rdev, radeon_crtc->crtc_id, base);
>   
> +	radeon_crtc->flip_status = RADEON_FLIP_SUBMITTED;
>   	spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
>   	up_read(&rdev->exclusive_lock);
>   
> @@ -543,7 +551,7 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
>   	/* We borrow the event spin lock for protecting flip_work */
>   	spin_lock_irqsave(&crtc->dev->event_lock, flags);
>   
> -	if (radeon_crtc->flip_work) {
> +	if (radeon_crtc->flip_status != RADEON_FLIP_NONE) {
>   		DRM_DEBUG_DRIVER("flip queue: crtc already busy\n");
>   		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
>   		drm_gem_object_unreference_unlocked(&work->old_rbo->gem_base);
> @@ -551,6 +559,7 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
>   		kfree(work);
>   		return -EBUSY;
>   	}
> +	radeon_crtc->flip_status = RADEON_FLIP_PENDING;
>   	radeon_crtc->flip_work = work;
>   
>   	/* update crtc fb */
> diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
> index b59096f..ed6b6e0 100644
> --- a/drivers/gpu/drm/radeon/radeon_mode.h
> +++ b/drivers/gpu/drm/radeon/radeon_mode.h
> @@ -301,6 +301,12 @@ struct radeon_atom_ss {
>   	uint16_t amount;
>   };
>   
> +enum radeon_flip_status {
> +	RADEON_FLIP_NONE,
> +	RADEON_FLIP_PENDING,
> +	RADEON_FLIP_SUBMITTED
> +};
> +
>   struct radeon_crtc {
>   	struct drm_crtc base;
>   	int crtc_id;
> @@ -326,6 +332,7 @@ struct radeon_crtc {
>   	/* page flipping */
>   	struct workqueue_struct *flip_queue;
>   	struct radeon_flip_work *flip_work;
> +	enum radeon_flip_status flip_status;
>   	/* pll sharing */
>   	struct radeon_atom_ss ss;
>   	bool ss_enabled;
Alex Deucher July 1, 2014, 4:23 p.m. UTC | #2 
On Mon, Jun 30, 2014 at 5:12 AM, Michel Dänzer <michel@daenzer.net> wrote:
> From: Michel Dänzer <michel.daenzer@amd.com>
>
> This prevents a panic: radeon_crtc_handle_page_flip() could run before
> radeon_flip_work_func(), triggering the BUG_ON() in drm_vblank_put().
>
> Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
> Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
> ---
>
> v2: Update log message

Applied to to by -fixes tree.

Alex

>
>  drivers/gpu/drm/radeon/radeon_display.c | 19 ++++++++++++++-----
>  drivers/gpu/drm/radeon/radeon_mode.h    |  7 +++++++
>  2 files changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
> index 8b575a4..65882cd 100644
> --- a/drivers/gpu/drm/radeon/radeon_display.c
> +++ b/drivers/gpu/drm/radeon/radeon_display.c
> @@ -284,7 +284,6 @@ static void radeon_unpin_work_func(struct work_struct *__work)
>  void radeon_crtc_handle_vblank(struct radeon_device *rdev, int crtc_id)
>  {
>         struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc_id];
> -       struct radeon_flip_work *work;
>         unsigned long flags;
>         u32 update_pending;
>         int vpos, hpos;
> @@ -294,8 +293,11 @@ void radeon_crtc_handle_vblank(struct radeon_device *rdev, int crtc_id)
>                 return;
>
>         spin_lock_irqsave(&rdev->ddev->event_lock, flags);
> -       work = radeon_crtc->flip_work;
> -       if (work == NULL) {
> +       if (radeon_crtc->flip_status != RADEON_FLIP_SUBMITTED) {
> +               DRM_DEBUG_DRIVER("radeon_crtc->flip_status = %d != "
> +                                "RADEON_FLIP_SUBMITTED(%d)\n",
> +                                radeon_crtc->flip_status,
> +                                RADEON_FLIP_SUBMITTED);
>                 spin_unlock_irqrestore(&rdev->ddev->event_lock, flags);
>                 return;
>         }
> @@ -343,12 +345,17 @@ void radeon_crtc_handle_flip(struct radeon_device *rdev, int crtc_id)
>
>         spin_lock_irqsave(&rdev->ddev->event_lock, flags);
>         work = radeon_crtc->flip_work;
> -       if (work == NULL) {
> +       if (radeon_crtc->flip_status != RADEON_FLIP_SUBMITTED) {
> +               DRM_DEBUG_DRIVER("radeon_crtc->flip_status = %d != "
> +                                "RADEON_FLIP_SUBMITTED(%d)\n",
> +                                radeon_crtc->flip_status,
> +                                RADEON_FLIP_SUBMITTED);
>                 spin_unlock_irqrestore(&rdev->ddev->event_lock, flags);
>                 return;
>         }
>
>         /* Pageflip completed. Clean up. */
> +       radeon_crtc->flip_status = RADEON_FLIP_NONE;
>         radeon_crtc->flip_work = NULL;
>
>         /* wakeup userspace */
> @@ -475,6 +482,7 @@ static void radeon_flip_work_func(struct work_struct *__work)
>         /* do the flip (mmio) */
>         radeon_page_flip(rdev, radeon_crtc->crtc_id, base);
>
> +       radeon_crtc->flip_status = RADEON_FLIP_SUBMITTED;
>         spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
>         up_read(&rdev->exclusive_lock);
>
> @@ -543,7 +551,7 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
>         /* We borrow the event spin lock for protecting flip_work */
>         spin_lock_irqsave(&crtc->dev->event_lock, flags);
>
> -       if (radeon_crtc->flip_work) {
> +       if (radeon_crtc->flip_status != RADEON_FLIP_NONE) {
>                 DRM_DEBUG_DRIVER("flip queue: crtc already busy\n");
>                 spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
>                 drm_gem_object_unreference_unlocked(&work->old_rbo->gem_base);
> @@ -551,6 +559,7 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
>                 kfree(work);
>                 return -EBUSY;
>         }
> +       radeon_crtc->flip_status = RADEON_FLIP_PENDING;
>         radeon_crtc->flip_work = work;
>
>         /* update crtc fb */
> diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
> index b59096f..ed6b6e0 100644
> --- a/drivers/gpu/drm/radeon/radeon_mode.h
> +++ b/drivers/gpu/drm/radeon/radeon_mode.h
> @@ -301,6 +301,12 @@ struct radeon_atom_ss {
>         uint16_t amount;
>  };
>
> +enum radeon_flip_status {
> +       RADEON_FLIP_NONE,
> +       RADEON_FLIP_PENDING,
> +       RADEON_FLIP_SUBMITTED
> +};
> +
>  struct radeon_crtc {
>         struct drm_crtc base;
>         int crtc_id;
> @@ -326,6 +332,7 @@ struct radeon_crtc {
>         /* page flipping */
>         struct workqueue_struct *flip_queue;
>         struct radeon_flip_work *flip_work;
> +       enum radeon_flip_status flip_status;
>         /* pll sharing */
>         struct radeon_atom_ss ss;
>         bool ss_enabled;
> --
> 2.0.0
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
diff mbox

Patch

diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index 8b575a4..65882cd 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -284,7 +284,6 @@  static void radeon_unpin_work_func(struct work_struct *__work)
 void radeon_crtc_handle_vblank(struct radeon_device *rdev, int crtc_id)
 {
 	struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc_id];
-	struct radeon_flip_work *work;
 	unsigned long flags;
 	u32 update_pending;
 	int vpos, hpos;
@@ -294,8 +293,11 @@  void radeon_crtc_handle_vblank(struct radeon_device *rdev, int crtc_id)
 		return;
 
 	spin_lock_irqsave(&rdev->ddev->event_lock, flags);
-	work = radeon_crtc->flip_work;
-	if (work == NULL) {
+	if (radeon_crtc->flip_status != RADEON_FLIP_SUBMITTED) {
+		DRM_DEBUG_DRIVER("radeon_crtc->flip_status = %d != "
+				 "RADEON_FLIP_SUBMITTED(%d)\n",
+				 radeon_crtc->flip_status,
+				 RADEON_FLIP_SUBMITTED);
 		spin_unlock_irqrestore(&rdev->ddev->event_lock, flags);
 		return;
 	}
@@ -343,12 +345,17 @@  void radeon_crtc_handle_flip(struct radeon_device *rdev, int crtc_id)
 
 	spin_lock_irqsave(&rdev->ddev->event_lock, flags);
 	work = radeon_crtc->flip_work;
-	if (work == NULL) {
+	if (radeon_crtc->flip_status != RADEON_FLIP_SUBMITTED) {
+		DRM_DEBUG_DRIVER("radeon_crtc->flip_status = %d != "
+				 "RADEON_FLIP_SUBMITTED(%d)\n",
+				 radeon_crtc->flip_status,
+				 RADEON_FLIP_SUBMITTED);
 		spin_unlock_irqrestore(&rdev->ddev->event_lock, flags);
 		return;
 	}
 
 	/* Pageflip completed. Clean up. */
+	radeon_crtc->flip_status = RADEON_FLIP_NONE;
 	radeon_crtc->flip_work = NULL;
 
 	/* wakeup userspace */
@@ -475,6 +482,7 @@  static void radeon_flip_work_func(struct work_struct *__work)
 	/* do the flip (mmio) */
 	radeon_page_flip(rdev, radeon_crtc->crtc_id, base);
 
+	radeon_crtc->flip_status = RADEON_FLIP_SUBMITTED;
 	spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
 	up_read(&rdev->exclusive_lock);
 
@@ -543,7 +551,7 @@  static int radeon_crtc_page_flip(struct drm_crtc *crtc,
 	/* We borrow the event spin lock for protecting flip_work */
 	spin_lock_irqsave(&crtc->dev->event_lock, flags);
 
-	if (radeon_crtc->flip_work) {
+	if (radeon_crtc->flip_status != RADEON_FLIP_NONE) {
 		DRM_DEBUG_DRIVER("flip queue: crtc already busy\n");
 		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
 		drm_gem_object_unreference_unlocked(&work->old_rbo->gem_base);
@@ -551,6 +559,7 @@  static int radeon_crtc_page_flip(struct drm_crtc *crtc,
 		kfree(work);
 		return -EBUSY;
 	}
+	radeon_crtc->flip_status = RADEON_FLIP_PENDING;
 	radeon_crtc->flip_work = work;
 
 	/* update crtc fb */
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index b59096f..ed6b6e0 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -301,6 +301,12 @@  struct radeon_atom_ss {
 	uint16_t amount;
 };
 
+enum radeon_flip_status {
+	RADEON_FLIP_NONE,
+	RADEON_FLIP_PENDING,
+	RADEON_FLIP_SUBMITTED
+};
+
 struct radeon_crtc {
 	struct drm_crtc base;
 	int crtc_id;
@@ -326,6 +332,7 @@  struct radeon_crtc {
 	/* page flipping */
 	struct workqueue_struct *flip_queue;
 	struct radeon_flip_work *flip_work;
+	enum radeon_flip_status flip_status;
 	/* pll sharing */
 	struct radeon_atom_ss ss;
 	bool ss_enabled;