This is a note to let you know that I've just added the patch titled
drm/i915: Fix gen6 (SNB) missed BLT ring interrupts.
to the 2.6.39-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-i915-fix-gen6-snb-missed-blt-ring-interrupts.patch
and it can be found in the queue-2.6.39 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <sta...@kernel.org> know about it.
>From 498e720b96379d8ee9c294950a01534a73defcf3 Mon Sep 17 00:00:00 2001
From: Daniel J Blueman <daniel.blue...@gmail.com>
Date: Fri, 17 Jun 2011 11:32:19 -0700
Subject: drm/i915: Fix gen6 (SNB) missed BLT ring interrupts.
From: Daniel J Blueman <daniel.blue...@gmail.com>
commit 498e720b96379d8ee9c294950a01534a73defcf3 upstream.
The failure appeared in dmesg as:
[drm:i915_hangcheck_ring_idle] *ERROR* Hangcheck timer elapsed... blt
ring idle [waiting on 35064155, at 35064155], missed IRQ?
This works around that problem on by making the blitter command
streamer write interrupt state to the Hardware Status Page when a
MI_USER_INTERRUPT command is decoded, which appears to force the seqno
out to memory before the interrupt happens.
v1->v2: Moved to prior interrupt handler installation and RMW flags as
per feedback.
v2->v3: Removed RMW of flags (by anholt)
Signed-off-by: Daniel J Blueman <daniel.blue...@gmail.com>
Signed-off-by: Eric Anholt <e...@anholt.net>
Tested-by: Chris Wilson <ch...@chris-wilson.co.uk> [v1]
Tested-by: Eric Anholt <e...@anholt.net> [v1,v3]
(incidence of the bug with a testcase went from avg 2/1000 to
0/12651 in the latest test run (plus more for v1))
Tested-by: Kenneth Graunke <kenn...@whitecape.org> [v1]
Tested-by: Robert Hooker <robert.hoo...@canonical.com> [v1]
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=33394
Signed-off-by: Dave Airlie <airl...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@suse.de>
---
drivers/gpu/drm/i915/i915_irq.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1567,6 +1567,16 @@ static void ironlake_irq_preinstall(stru
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
I915_WRITE(HWSTAM, 0xeffe);
+ if (IS_GEN6(dev)) {
+ /* Workaround stalls observed on Sandy Bridge GPUs by
+ * making the blitter command streamer generate a
+ * write to the Hardware Status Page for
+ * MI_USER_INTERRUPT. This appears to serialize the
+ * previous seqno write out before the interrupt
+ * happens.
+ */
+ I915_WRITE(GEN6_BLITTER_HWSTAM, ~GEN6_BLITTER_USER_INTERRUPT);
+ }
/* XXX hotplug from PCH */
Patches currently in stable-queue which might be from daniel.blue...@gmail.com
are
queue-2.6.39/drm-i915-fix-gen6-snb-missed-blt-ring-interrupts.patch
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