linux-kernel - [PATCH 5.12 122/127] drm/i915/gt: Disable HiZ Raw Stall Optimization on broken gen7

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Date:   Mon, 24 May 2021 17:27:19 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Manuel Bentele <development@...uel-bentele.de>,
        Simon Rettberg <simon.rettberg@...uni-freiburg.de>,
        Dave Airlie <airlied@...hat.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        Jani Nikula <jani.nikula@...el.com>
Subject: [PATCH 5.12 122/127] drm/i915/gt: Disable HiZ Raw Stall Optimization on broken gen7

From: Simon Rettberg <simon.rettberg@...uni-freiburg.de>

commit 023dfa9602f561952c0e19d74f66614a56d7e57a upstream.

When resetting CACHE_MODE registers, don't enable HiZ Raw Stall
Optimization on Ivybridge GT1 and Baytrail, as it causes severe glitches
when rendering any kind of 3D accelerated content.
This optimization is disabled on these platforms by default according to
official documentation from 01.org.

Fixes: ef99a60ffd9b ("drm/i915/gt: Clear CACHE_MODE prior to clearing residuals")
BugLink: https://gitlab.freedesktop.org/drm/intel/-/issues/3081
BugLink: https://gitlab.freedesktop.org/drm/intel/-/issues/3404
BugLink: https://gitlab.freedesktop.org/drm/intel/-/issues/3071
Reviewed-by: Manuel Bentele <development@...uel-bentele.de>
Signed-off-by: Simon Rettberg <simon.rettberg@...uni-freiburg.de>
Reviewed-by: Dave Airlie <airlied@...hat.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@...el.com>
[Rodrigo removed invalid Fixes line]
Link: https://patchwork.freedesktop.org/patch/msgid/20210426161124.2b7fd708@dellnichtsogutkiste
(cherry picked from commit 929b734ad34b717d6a1b8de97f53bb5616040147)
Signed-off-by: Jani Nikula <jani.nikula@...el.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/gpu/drm/i915/gt/gen7_renderclear.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/gt/gen7_renderclear.c
+++ b/drivers/gpu/drm/i915/gt/gen7_renderclear.c
@@ -397,7 +397,10 @@ static void emit_batch(struct i915_vma *
 	gen7_emit_pipeline_invalidate(&cmds);
 	batch_add(&cmds, MI_LOAD_REGISTER_IMM(2));
 	batch_add(&cmds, i915_mmio_reg_offset(CACHE_MODE_0_GEN7));
-	batch_add(&cmds, 0xffff0000);
+	batch_add(&cmds, 0xffff0000 |
+			((IS_IVB_GT1(i915) || IS_VALLEYVIEW(i915)) ?
+			 HIZ_RAW_STALL_OPT_DISABLE :
+			 0));
 	batch_add(&cmds, i915_mmio_reg_offset(CACHE_MODE_1));
 	batch_add(&cmds, 0xffff0000 | PIXEL_SUBSPAN_COLLECT_OPT_DISABLE);
 	gen7_emit_pipeline_invalidate(&cmds);