From: Daniel Vetter Date: Wed, 4 Jul 2012 20:18:41 +0000 (+0200) Subject: drm/i915: don't hang userspace when the gpu reset is stuck X-Git-Tag: v3.6-rc1~83^2~39^2~8 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=0a6759c6bacb3998e3d9a7cf690177051238ad87;p=~emulex%2Finfiniband.git 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 Tested-by: Chris Wilson Signed-Off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index af6a510367a..7d285554333 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -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