From a2b6d3b33b6a255a271fb120cdc37c6757cdd2be Mon Sep 17 00:00:00 2001 From: =?utf8?q?Michel=20D=C3=A4nzer?= Date: Mon, 30 Jun 2014 18:12:34 +0900 Subject: [PATCH] drm/radeon: Track the status of a page flip more explicitly MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Christian König Signed-off-by: Michel Dänzer Signed-off-by: Alex Deucher --- 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 8fc362a..13896ed 100644 --- a/drivers/gpu/drm/radeon/radeon_display.c +++ b/drivers/gpu/drm/radeon/radeon_display.c @@ -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 */ diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h index 98a125d..0592ddb 100644 --- a/drivers/gpu/drm/radeon/radeon_mode.h +++ b/drivers/gpu/drm/radeon/radeon_mode.h @@ -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; -- 2.7.4