Here is the final patch, and as you can see it's quite small.. This should hit upstream in the not-too-distant future.
Date: Fri, 06 Feb 2009 13:04:49 -0800 From: Jesse Barnes <jbar...@virtuousgeek.org> To: Dave Airlie <airl...@linux.ie> Cc: DRI <dri-de...@lists.sourceforge.net>, Timo Aaltonen <tjaal...@cc.hut.fi>, Michel Dänzer <mic...@tungstengraphics.com> Subject: [PATCH] capture last_vblank count at IRQ uninstall time too In dc1336ff4fe08ae7cfe8301bfd7f0b2cfd31d20a (set vblank enable flag correctly across IRQ uninstall), we made sure drivers that uninstall their interrupt handler set the vblank enabled flag correctly, so that when interrupts are re-enabled, vblank interrupts & counts work as expected. However I missed the last_vblank field: it needs to be updated as well, otherwise, at the next drm_update_vblank_count we'll end up comparing a current count to a stale one (the last one captured by the disable function), which may trigger the wraparound handling, leading to a jumpy counter and hangs in drm_wait_vblank. The jumpy counter can prevent the DRM_WAIT_ON from returning success if the difference between the current count and the requested count is greater than 2^23, leading to timeouts or hangs, if the ioctl is restarted in a loop (as is the case in libdrm < 2.4.4). Signed-off-by: Jesse Barnes <jbar...@virtuousgeek.org> diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 69aa0ab..3795dbc 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -276,6 +276,7 @@ int drm_irq_uninstall(struct drm_device * dev) for (i = 0; i < dev->num_crtcs; i++) { DRM_WAKEUP(&dev->vbl_queue[i]); dev->vblank_enabled[i] = 0; + dev->last_vblank[i] = dev->driver->get_vblank_counter(dev, i); } spin_unlock_irqrestore(&dev->vbl_lock, irqflags); -- [drm] compiz animations cause temporary freezes with vblank https://bugs.launchpad.net/bugs/320813 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs