From: Mario Kleiner Date: Fri, 6 May 2016 17:26:06 +0000 (+0200) Subject: drm/vc4: Fix drm_vblank_put/get imbalance in page flip path. X-Git-Tag: v4.7-rc3~21^2~4^2~3 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=ee7c10e10b632e2319ed1d2d49d63df51a611e62;p=linux.git drm/vc4: Fix drm_vblank_put/get imbalance in page flip path. The async page flip path was missing drm_crtc_vblank_get/put completely. The sync flip path was missing a vblank put, so async flips only reported proper pageflip completion events by chance, and vblank irq's never turned off after a first vsync'ed page flip until system reboot. Tested against Raspian kernel 4.4.8 tree on RPi 2B. Signed-off-by: Mario Kleiner Reviewed-by: Eric Anholt Fixes: b501bacc6060 ("drm/vc4: Add support for async pageflips.") --- diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c index 904d0754ad78..e9befb6d10fd 100644 --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -506,6 +506,7 @@ static void vc4_crtc_handle_page_flip(struct vc4_crtc *vc4_crtc) if (vc4_crtc->event) { drm_crtc_send_vblank_event(crtc, vc4_crtc->event); vc4_crtc->event = NULL; + drm_crtc_vblank_put(crtc); } spin_unlock_irqrestore(&dev->event_lock, flags); } @@ -556,6 +557,7 @@ vc4_async_page_flip_complete(struct vc4_seqno_cb *cb) spin_unlock_irqrestore(&dev->event_lock, flags); } + drm_crtc_vblank_put(crtc); drm_framebuffer_unreference(flip_state->fb); kfree(flip_state); @@ -598,6 +600,8 @@ static int vc4_async_page_flip(struct drm_crtc *crtc, return ret; } + WARN_ON(drm_crtc_vblank_get(crtc) != 0); + /* Immediately update the plane's legacy fb pointer, so that later * modeset prep sees the state that will be present when the semaphore * is released.