@@ -139,8 +139,20 @@ intel_pin_and_fence_fb_obj(struct drm_framebuffer *fb,
ret = i915_gem_object_lock(obj, &ww);
if (!ret && phys_cursor)
ret = i915_gem_object_attach_phys(obj, alignment);
- else if (!ret && HAS_LMEM(dev_priv))
- ret = i915_gem_object_migrate(obj, &ww, INTEL_REGION_LMEM_0);
+ else if (!ret && HAS_LMEM(dev_priv)) {
+ unsigned int flags = obj->flags;
+
+ /*
+ * For this type of buffer we need to able to read from the CPU
+ * the clear color value found in the buffer, hence we need to
+ * ensure it is always in the mappable part of lmem, if this is
+ * a small-bar device.
+ */
+ if (intel_fb_rc_ccs_cc_plane(fb) >= 0)
+ flags &= ~I915_BO_ALLOC_GPU_ONLY;
+ ret = __i915_gem_object_migrate(obj, &ww, INTEL_REGION_LMEM_0,
+ flags);
+ }
if (!ret)
ret = i915_gem_object_pin_pages(obj);
if (ret)
For these types of display buffers, we need to able to CPU access some part of the backing memory in prepare_plane_clear_colors(). As a result we need to ensure we always place in the mappable part of lmem, which becomes necessary on small-bar systems. v2(Nirmoy & Ville): - Add some commentary for why we need to CPU access the buffer. - Split out the other changes, so we just consider the display change here. Fixes: eb1c535f0d69 ("drm/i915: turn on small BAR support") Reported-by: Jianshui Yu <jianshui.yu@intel.com> Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Nirmoy Das <nirmoy.das@intel.com> Reviewed-by: Nirmoy Das <nirmoy.das@intel.com> --- drivers/gpu/drm/i915/display/intel_fb_pin.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)