diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.9/950-0166-drm-vc4-Fix-race-between-page-flip-completion-event-.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.9/950-0166-drm-vc4-Fix-race-between-page-flip-completion-event-.patch | 93 |
1 files changed, 0 insertions, 93 deletions
diff --git a/target/linux/brcm2708/patches-4.9/950-0166-drm-vc4-Fix-race-between-page-flip-completion-event-.patch b/target/linux/brcm2708/patches-4.9/950-0166-drm-vc4-Fix-race-between-page-flip-completion-event-.patch deleted file mode 100644 index 3c66fefafd..0000000000 --- a/target/linux/brcm2708/patches-4.9/950-0166-drm-vc4-Fix-race-between-page-flip-completion-event-.patch +++ /dev/null @@ -1,93 +0,0 @@ -From d7f32f81cf7579ac7d13127db88e789ea864824c Mon Sep 17 00:00:00 2001 -From: Derek Foreman <derekf@osg.samsung.com> -Date: Thu, 24 Nov 2016 12:11:55 -0600 -Subject: [PATCH] drm/vc4: Fix race between page flip completion event and - clean-up - -There was a small window where a userspace program could submit -a pageflip after receiving a pageflip completion event yet still -receive EBUSY. - -Signed-off-by: Derek Foreman <derekf@osg.samsung.com> -Signed-off-by: Eric Anholt <eric@anholt.net> -Reviewed-by: Eric Anholt <eric@anholt.net> -Reviewed-by: Daniel Stone <daniels@collabora.com> -(cherry picked from commit 26fc78f6fef39b9d7a15def5e7e9826ff68303f4) ---- - drivers/gpu/drm/vc4/vc4_crtc.c | 8 ++++++++ - drivers/gpu/drm/vc4/vc4_drv.h | 1 + - drivers/gpu/drm/vc4/vc4_kms.c | 33 +++++++++++++++++++++++++-------- - 3 files changed, 34 insertions(+), 8 deletions(-) - ---- a/drivers/gpu/drm/vc4/vc4_crtc.c -+++ b/drivers/gpu/drm/vc4/vc4_crtc.c -@@ -682,6 +682,14 @@ void vc4_disable_vblank(struct drm_devic - CRTC_WRITE(PV_INTEN, 0); - } - -+/* Must be called with the event lock held */ -+bool vc4_event_pending(struct drm_crtc *crtc) -+{ -+ struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc); -+ -+ return !!vc4_crtc->event; -+} -+ - static void vc4_crtc_handle_page_flip(struct vc4_crtc *vc4_crtc) - { - struct drm_crtc *crtc = &vc4_crtc->base; ---- a/drivers/gpu/drm/vc4/vc4_drv.h -+++ b/drivers/gpu/drm/vc4/vc4_drv.h -@@ -445,6 +445,7 @@ int vc4_bo_stats_debugfs(struct seq_file - extern struct platform_driver vc4_crtc_driver; - int vc4_enable_vblank(struct drm_device *dev, unsigned int crtc_id); - void vc4_disable_vblank(struct drm_device *dev, unsigned int crtc_id); -+bool vc4_event_pending(struct drm_crtc *crtc); - int vc4_crtc_debugfs_regs(struct seq_file *m, void *arg); - int vc4_crtc_get_scanoutpos(struct drm_device *dev, unsigned int crtc_id, - unsigned int flags, int *vpos, int *hpos, ---- a/drivers/gpu/drm/vc4/vc4_kms.c -+++ b/drivers/gpu/drm/vc4/vc4_kms.c -@@ -119,17 +119,34 @@ static int vc4_atomic_commit(struct drm_ - - /* Make sure that any outstanding modesets have finished. */ - if (nonblock) { -- ret = down_trylock(&vc4->async_modeset); -- if (ret) { -+ struct drm_crtc *crtc; -+ struct drm_crtc_state *crtc_state; -+ unsigned long flags; -+ bool busy = false; -+ -+ /* -+ * If there's an undispatched event to send then we're -+ * obviously still busy. If there isn't, then we can -+ * unconditionally wait for the semaphore because it -+ * shouldn't be contended (for long). -+ * -+ * This is to prevent a race where queuing a new flip -+ * from userspace immediately on receipt of an event -+ * beats our clean-up and returns EBUSY. -+ */ -+ spin_lock_irqsave(&dev->event_lock, flags); -+ for_each_crtc_in_state(state, crtc, crtc_state, i) -+ busy |= vc4_event_pending(crtc); -+ spin_unlock_irqrestore(&dev->event_lock, flags); -+ if (busy) { - kfree(c); - return -EBUSY; - } -- } else { -- ret = down_interruptible(&vc4->async_modeset); -- if (ret) { -- kfree(c); -- return ret; -- } -+ } -+ ret = down_interruptible(&vc4->async_modeset); -+ if (ret) { -+ kfree(c); -+ return ret; - } - - ret = drm_atomic_helper_prepare_planes(dev, state); |