drm/radeon: bail early from enable ss in certain cases
If the ss percentage is 0 or we are using external ss,
just bail when enabling ss. We disable it explicitly
earlier in the modeset already.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index fd9daf4..4cf6783 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -423,7 +423,17 @@
int index = GetIndexIntoMasterTable(COMMAND, EnableSpreadSpectrumOnPPLL);
union atom_enable_ss args;
- if (!enable) {
+ if (enable) {
+ /* Don't mess with SS if percentage is 0 or external ss.
+ * SS is already disabled previously, and disabling it
+ * again can cause display problems if the pll is already
+ * programmed.
+ */
+ if (ss->percentage == 0)
+ return;
+ if (ss->type & ATOM_EXTERNAL_SS_MASK)
+ return;
+ } else {
for (i = 0; i < rdev->num_crtc; i++) {
if (rdev->mode_info.crtcs[i] &&
rdev->mode_info.crtcs[i]->enabled &&
@@ -459,8 +469,6 @@
args.v3.usSpreadSpectrumAmount = cpu_to_le16(ss->amount);
args.v3.usSpreadSpectrumStep = cpu_to_le16(ss->step);
args.v3.ucEnable = enable;
- if ((ss->percentage == 0) || (ss->type & ATOM_EXTERNAL_SS_MASK) || ASIC_IS_DCE61(rdev))
- args.v3.ucEnable = ATOM_DISABLE;
} else if (ASIC_IS_DCE4(rdev)) {
args.v2.usSpreadSpectrumPercentage = cpu_to_le16(ss->percentage);
args.v2.ucSpreadSpectrumType = ss->type & ATOM_SS_CENTRE_SPREAD_MODE_MASK;
@@ -480,8 +488,6 @@
args.v2.usSpreadSpectrumAmount = cpu_to_le16(ss->amount);
args.v2.usSpreadSpectrumStep = cpu_to_le16(ss->step);
args.v2.ucEnable = enable;
- if ((ss->percentage == 0) || (ss->type & ATOM_EXTERNAL_SS_MASK) || ASIC_IS_DCE41(rdev))
- args.v2.ucEnable = ATOM_DISABLE;
} else if (ASIC_IS_DCE3(rdev)) {
args.v1.usSpreadSpectrumPercentage = cpu_to_le16(ss->percentage);
args.v1.ucSpreadSpectrumType = ss->type & ATOM_SS_CENTRE_SPREAD_MODE_MASK;
@@ -503,8 +509,7 @@
args.lvds_ss_2.ucSpreadSpectrumRange = ss->range;
args.lvds_ss_2.ucEnable = enable;
} else {
- if ((enable == ATOM_DISABLE) || (ss->percentage == 0) ||
- (ss->type & ATOM_EXTERNAL_SS_MASK)) {
+ if (enable == ATOM_DISABLE) {
atombios_disable_ss(rdev, pll_id);
return;
}