On Wed, 2011-04-27 at 17:50 +0200, Mario Kleiner wrote:
On Apr 27, 2011, at 10:58 AM, dri-devel-request@lists.freedesktop.org wrote:
Message: 5 Date: Wed, 27 Apr 2011 10:38:14 +0200 From: Michel D?nzer michel@daenzer.net Subject: Re: [PATCH 2/3] drm: Warn if vblank state has become inconsistent. To: christopher.halse.rogers@canonical.com Cc: dri-devel@lists.freedesktop.org Message-ID: 1303893494.5633.129.camel@thor.local Content-Type: text/plain; charset="UTF-8"
On Mit, 2011-04-27 at 16:10 +1000, christopher.halse.rogers@canonical.com wrote:
From: Christopher James Halse Rogers christopher.halse.rogers@canonical.com
After emitting all the waiting vblank events no-one should hold a vblank reference. Emit a warning if this is not the case.
Signed-off-by: Christopher James Halse Rogers
christopher.halse.rogers@canonical.com
drivers/gpu/drm/drm_irq.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index a1f12cb..72407fa 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -960,6 +960,7 @@ void drm_vblank_off(struct drm_device *dev, int crtc) e->event.sequence); }
- WARN_ON(atomic_read(&dev->vblank_refcount[crtc]) != 0); spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
} EXPORT_SYMBOL(drm_vblank_off);
Reviewed-by: Michel D?nzer michel@daenzer.net
Any pending kms pageflip will also hold a reference on the vblank of a crtc, so having the refcount non-zero there is not really a sign of inconsistency, so i'm not sure if a warning is appropriate there.
But at this point the vblank interrupts have been disabled, or at least the driver's disable function has been called. Will that not mean that any pending pageflips will wait indefinitely for a vblank interrupt that's not going to come - ie: exactly the state we're warning against?