From: Ben Widawsky Date: Thu, 24 May 2012 22:03:10 +0000 (-0700) Subject: drm/i915: wait render timeout ioctl X-Git-Tag: v3.6-rc1~83^2~47^2~30 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=23ba4fd0a42a46551041e379712e808ad496ba45;p=pandora-kernel.git drm/i915: wait render timeout ioctl This helps implement GL_ARB_sync but stops short of allowing full blown sync objects. Finally we can use the new timed seqno waiting function to allow userspace to wait on a buffer object with a timeout. This implements that interface. The IOCTL will take as input a buffer object handle, and a timeout in nanoseconds (flags is currently optional but will likely be used for permutations of flush operations). Users may specify 0 nanoseconds to instantly check. The wait ioctl with a timeout of 0 reimplements the busy ioctl. With any non-zero timeout parameter the wait ioctl will wait for the given number of nanoseconds on an object becoming unbusy. Since the wait itself does so holding struct_mutex the object may become re-busied before this completes. A similar but shorter race condition exists in the busy ioctl. v2: ETIME/ERESTARTSYS instead of changing to EBUSY, and EGAIN (Chris) Flush the object from the gpu write domain (Chris + Daniel) Fix leaked refcount in good case (Chris) Naturally align ioctl struct (Chris) v3: Drop lock after getting seqno to avoid ugly dance (Chris) v4: check for 0 timeout after olr check to allow polling (Chris) v5: Updated the comment. (Chris) v6: Return -ETIME instead of -EBUSY when timeout_ns is 0 (Daniel) Fix the commit message comment to be less ugly (Ben) Add a warning to check the return timespec (Ben) v7: Use DRM_AUTH for the ioctl. (Eugeni) Signed-off-by: Ben Widawsky Signed-off-by: Daniel Vetter --- Reading git-diff-tree failed