drm/i915: don't hang userspace when the gpu reset is stuck

With the gpu reset no longer using a trylock we've increased the
chances of userspace getting stuck quite a bit. To make that
(hopefully) rare case more paletable time out when waiting for the gpu
reset code to complete and signal this little issue to the caller by
returning -EIO.

This should help userspace to somewhat gracefully fall back and
hopefully allow the user to grab some logs and reboot the machine
(instead of staring at a frozen X screen in agony).

Suggested by Chris Wilson because I've been stubborn about allowing
the gpu reset code no to fail, ever (by removing the trylock).

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Daniel Vetter 2012-07-04 22:18:41 +02:00
parent d6b2c790a4
commit 0a6759c6ba

View File

@ -96,9 +96,18 @@ i915_gem_wait_for_error(struct drm_device *dev)
if (!atomic_read(&dev_priv->mm.wedged))
return 0;
ret = wait_for_completion_interruptible(x);
if (ret)
/*
* Only wait 10 seconds for the gpu reset to complete to avoid hanging
* userspace. If it takes that long something really bad is going on and
* we should simply try to bail out and fail as gracefully as possible.
*/
ret = wait_for_completion_interruptible_timeout(x, 10*HZ);
if (ret == 0) {
DRM_ERROR("Timed out waiting for the gpu reset to complete\n");
return -EIO;
} else if (ret < 0) {
return ret;
}
if (atomic_read(&dev_priv->mm.wedged)) {
/* GPU is hung, bump the completion count to account for