From: Eric Anholt <eric@anholt.net>
Date: Thu, 22 Dec 2011 22:55:00 +0000 (-0800)
Subject: drm/i915: Work around gen7 BLT ring synchronization issues.
X-Git-Tag: v3.3-rc1~121^2~32
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=42ff6572e5a4a7414330a4ca91f0335da67deca9;p=pandora-kernel.git

drm/i915: Work around gen7 BLT ring synchronization issues.

Previous to this commit, testing easily reproduced a failure where the
seqno would apparently arrive after the IRQ associated with it, with test programs as simple as:

for (;;) {
    glCopyPixels(0, 0, 1, 1);
    glFinish();
}

Various workarounds we've seen for previous generations didn't work to
fix this issue, so until new information comes in, replace the IRQ
waits on the BLT ring with polling.

Signed-off-by: Eric Anholt <eric@anholt.net>
Tested-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Acked-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
---

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