Commit a2b6d3b3 authored by Michel Dänzer's avatar Michel Dänzer Committed by Alex Deucher
Browse files

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



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: default avatarDieter Nützel <Dieter@nuetzel-hh.de>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarMichel Dänzer <michel.daenzer@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent b0880e87

drivers/gpu/drm/radeon/radeon_display.c

+14 −5
Original line number Diff line number Diff line
@@ -285,7 +285,6 @@ 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;
@@ -295,8 +294,11 @@ 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;

	}
@@ -344,12 +346,17 @@ 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 */
@@ -476,6 +483,7 @@ 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);
@@ -544,7 +552,7 @@ 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);
@@ -552,6 +560,7 @@ 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 */

drivers/gpu/drm/radeon/radeon_mode.h

+7 −0
Original line number Diff line number Diff line
@@ -306,6 +306,12 @@ 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;
@@ -331,6 +337,7 @@ 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;

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