From: Daniel J Blueman Subject: [PATCH 3.0-rc3, v2] i915: Fix gen6 (SNB) GPU stalling Date: Sat, 18 Jun 2011 00:42:00 +0800 Message-ID: <1308328920-2068-1-git-send-email-daniel.blueman@gmail.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Eric Anholt , Dave Airlie Cc: Chris Wilson , intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, Ben Widawsky , Kenneth Graunke , Yi Sun , Jesse Barnes , Mengmeng Meng , Robert Hooker , Daniel J Blueman List-Id: intel-gfx@lists.freedesktop.org Workaround Sandy Bridge GPU stalls by allowing the blitter command streamer to write interrupt state to the Hardware Status Page when a MI_USER_INTERRUPT command is decoded. v1->v2: Moved to prior interrupt handler installation and RMW flags as per feedback. Eric, if you're happy, please sign-off and send to Dave for inclusion in -rc4 if possible. Further changes may be needed for -stable. Signed-off-by: Daniel J Blueman --- drivers/gpu/drm/i915/i915_irq.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index b9fafe3..b7f11a5 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1741,6 +1741,13 @@ void ironlake_irq_preinstall(struct drm_device *dev) I915_WRITE(HWSTAM, 0xeffe); + if (IS_GEN6(dev)) + /* workaround stalls observed on Sandy Bridge GPUs by + allowing the blitter command streamer to generate a + write to the Hardware Status Page for MI_USER_INTERRUPT */ + I915_WRITE(GEN6_BLITTER_HWSTAM, I915_READ(GEN6_BLITTER_HWSTAM) + & ~GEN6_BLITTER_USER_INTERRUPT); + /* XXX hotplug from PCH */ I915_WRITE(DEIMR, 0xffffffff); -- 1.7.4.1