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From 4ade7daf2f840cba975769bb95b357c4584cf25d Mon Sep 17 00:00:00 2001
From: Matthew Auld <matthew.auld@intel.com>
Date: Wed, 22 Jun 2022 16:59:19 +0100
Subject: drm/i915: tweak the ordering in cpu_write_needs_clflush
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Alt-commit: 563aaf4a928def2d36d1b3de0a4b515e2477b4da
Git-commit: 79538490fd7ade244dba400923e792519a2bdfea
Patch-mainline: v5.19-rc5
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

For imported dma-buf objects we leave the object as cache_coherent = 0
across all platforms, which is reasonable given that have no clue what
the memory underneath is, and its not like the driver can ever manually
clflush the pages anyway (like with i915_gem_clflush_object) for such
objects. However on discrete we choose to treat cache_dirty = true as a
programmer error, leading to a warning. The simplest fix looks to be to
just change the ordering in cpu_write_needs_clflush to prevent ever
setting cache_dirty for dma-buf objects on discrete.

Fixes: d028a7690d87 ("drm/i915/dmabuf: Fix prime_mmap to work when using LMEM")
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5266
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220622155919.355081-1-matthew.auld@intel.com
(cherry picked from commit 563aaf4a928def2d36d1b3de0a4b515e2477b4da)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/gem/i915_gem_domain.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
index 3e5d6057b3ef..1674b0c5802b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_domain.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
@@ -35,12 +35,12 @@ bool i915_gem_cpu_write_needs_clflush(struct drm_i915_gem_object *obj)
 	if (obj->cache_dirty)
 		return false;
 
-	if (!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE))
-		return true;
-
 	if (IS_DGFX(i915))
 		return false;
 
+	if (!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE))
+		return true;
+
 	/* Currently in use by HW (display engine)? Keep flushed. */
 	return i915_gem_object_is_framebuffer(obj);
 }
-- 
2.38.1