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 --- 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); }