drm/radeon/dpm: disable ss on Cayman
Spread spectrum seems to cause hangs when dynamic clock
switching is enabled. Disable it for now. This does not
affect performance or the amount of power saved. Tracked
down by Martin Andersson.
bug:
https://bugs.freedesktop.org/show_bug.cgi?id=69723
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/radeon/rv770_dpm.c b/drivers/gpu/drm/radeon/rv770_dpm.c
index 913b025..374499d 100644
--- a/drivers/gpu/drm/radeon/rv770_dpm.c
+++ b/drivers/gpu/drm/radeon/rv770_dpm.c
@@ -2328,6 +2328,12 @@
pi->mclk_ss = radeon_atombios_get_asic_ss_info(rdev, &ss,
ASIC_INTERNAL_MEMORY_SS, 0);
+ /* disable ss, causes hangs on some cayman boards */
+ if (rdev->family == CHIP_CAYMAN) {
+ pi->sclk_ss = false;
+ pi->mclk_ss = false;
+ }
+
if (pi->sclk_ss || pi->mclk_ss)
pi->dynamic_ss = true;
else