[src/trunk]: src/sys/external/bsd/drm2/dist/drm/i915 Fix return code of __wai...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3e386049fbac
branches:  trunk
changeset: 336353:3e386049fbac
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Thu Feb 26 19:43:43 2015 +0000

description:
Fix return code of __wait_seqno.

MAX(ret, 0) is 0 if ret is negative, but if ret is negative we want
to return that negative value, meaning error.  Should've been
MIN(ret, 0), but I'll just rewrite it to clarify a wee bit.

If the GPU reset, call i915_gem_check_wedge and always return failure
like Linux does.  Caller must retry in that case.

diffstat:

 sys/external/bsd/drm2/dist/drm/i915/i915_gem.c |  10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletions(-)

diffs (20 lines):

diff -r d7a1324c4ea4 -r 3e386049fbac sys/external/bsd/drm2/dist/drm/i915/i915_gem.c
--- a/sys/external/bsd/drm2/dist/drm/i915/i915_gem.c    Thu Feb 26 16:07:10 2015 +0000
+++ b/sys/external/bsd/drm2/dist/drm/i915/i915_gem.c    Thu Feb 26 19:43:43 2015 +0000
@@ -1457,7 +1457,15 @@
                else
                        timespecclear(timeout);
        }
-       return MAX(ret, 0);     /* ignore remaining ticks */
+       if (wedged) {           /* GPU reset while we were waiting.  */
+               ret = i915_gem_check_wedge(&dev_priv->gpu_error,
+                   interruptible);
+               if (ret == 0)
+                       ret = -EAGAIN;
+       }
+       if (ret < 0)            /* Failure.  */
+               return ret;
+       return 0;               /* Success, possibly with time to spare.  */
 }
 #else
 static int __wait_seqno(struct intel_ring_buffer *ring, u32 seqno,