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 <mario.kleiner.de@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
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 904d075..e9befb6 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -506,6 +506,7 @@
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 @@
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 @@
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.