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| author | Michel Dänzer <michel.daenzer@amd.com> | 2015-02-04 02:19:51 +0100 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2015-02-11 18:01:33 +0100 |
| commit | a53fa43873b88bad15a2eb1f01dc5efa689625ce (patch) | |
| tree | 2513dcac20515684498f4530f8c834866125e480 /drivers/gpu/drm | |
| parent | drm/radeon: use 0-255 rather than 0-100 for pwm fan range (diff) | |
| download | linux-a53fa43873b88bad15a2eb1f01dc5efa689625ce.tar.xz linux-a53fa43873b88bad15a2eb1f01dc5efa689625ce.zip | |
drm/radeon: Don't try to enable write-combining without PAT
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
Cc: stable@vger.kernel.org
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/radeon/radeon_object.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c index 1d955776f4d0..43e09942823e 100644 --- a/drivers/gpu/drm/radeon/radeon_object.c +++ b/drivers/gpu/drm/radeon/radeon_object.c @@ -238,6 +238,18 @@ 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); |