On 24/10/2025 13:53, Tvrtko Ursulin wrote:
On 24/10/2025 12:04, Jocelyn Falempe wrote:
On a lenovo se100 server, when using i915 GPU for rendering, and the
ast driver for display, the graphic output is corrupted, and almost
unusable.
Adding a clflush call in the vmap function fixes this issue
completely.
AST is importing i915 allocated buffer in this use case, or how exactly
is the relationship?
I think it's mutter/gnome-shell who copy the buffer from i915 to ast,
here is the logs:
gnome-shell[2079]: Failed to initialize accelerated iGPU/dGPU
framebuffer sharing: Do not want to use software renderer (llvmpipe
(LLVM 19.1.7, 256 bits)), falling back to CPU copy path
gnome-shell[1533]: Created gbm renderer for '/dev/dri/card0'
gnome-shell[1533]: GPU /dev/dri/card1 selected as primary
card0 is ast and card1 is i915
Do you think there is something missing in mutter?
(Added Michel Dänzer that may know more about mutter).
--
Jocelyn
Wondering if some path is not calling dma_buf_begin/end_cpu_access().
Regards,
Tvrtko
Signed-off-by: Jocelyn Falempe <[email protected]>
---
drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/
drm/i915/gem/i915_gem_dmabuf.c
index f4f1c979d1b9..f6a8c1cbe4d1 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
@@ -77,6 +77,7 @@ static int i915_gem_dmabuf_vmap(struct dma_buf
*dma_buf,
return PTR_ERR(vaddr);
iosys_map_set_vaddr(map, vaddr);
+ drm_clflush_virt_range(vaddr, dma_buf->size);
return 0;
}
base-commit: 0790925dadad0997580df6e32cdccd54316807f2
