From: Michel Dänzer <[email protected]> commit a53fa43873b88bad15a2eb1f01dc5efa689625ce upstream.
Doing so can cause things to become slow. Print a warning at compile time and an informative message at runtime in that case. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88758 Reviewed-by: Christian König <[email protected]> Signed-off-by: Michel Dänzer <[email protected]> Signed-off-by: Alex Deucher <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- drivers/gpu/drm/radeon/radeon_object.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c index 4c0d786..194f624 100644 --- a/drivers/gpu/drm/radeon/radeon_object.c +++ b/drivers/gpu/drm/radeon/radeon_object.c @@ -218,6 +218,18 @@ int radeon_bo_create(struct radeon_device *rdev, * See https://bugs.freedesktop.org/show_bug.cgi?id=84627 */ bo->flags &= ~RADEON_GEM_GTT_WC; +#elif defined(CONFIG_X86) && !defined(CONFIG_X86_PAT) + /* Don't try to enable write-combining when it can't work, or things + * may be slow + * See https://bugs.freedesktop.org/show_bug.cgi?id=88758 + */ + +#warning Please enable CONFIG_MTRR and CONFIG_X86_PAT for better performance \ + thanks to write-combining + + DRM_INFO_ONCE("Please enable CONFIG_MTRR and CONFIG_X86_PAT for " + "better performance thanks to write-combining\n"); + bo->flags &= ~RADEON_GEM_GTT_WC; #endif radeon_ttm_placement_from_domain(bo, domain); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
