drm/radeon/kms: fix up DP clock programming on DCE4/5
In DP mode, the DP ref clock can come from PPLL, DCPLL, or ext clock,
depending on the asic. The crtc virtual pixel clock is derived from
the DP ref clock.
- DCE4: PPLL or ext clock
- DCE5: DCPLL or ext clock
Setting ATOM_PPLL_INVALID will cause SetPixelClock to skip
PPLL/DCPLL programming and only program the DP DTO for the
crtc virtual pixel clock.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index ff0d1ca..9770aff 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -1443,11 +1443,19 @@
uint32_t pll_in_use = 0;
if (ASIC_IS_DCE4(rdev)) {
- /* if crtc is driving DP and we have an ext clock, use that */
list_for_each_entry(test_encoder, &dev->mode_config.encoder_list, head) {
if (test_encoder->crtc && (test_encoder->crtc == crtc)) {
+ /* in DP mode, the DP ref clock can come from PPLL, DCPLL, or ext clock,
+ * depending on the asic:
+ * DCE4: PPLL or ext clock
+ * DCE5: DCPLL or ext clock
+ *
+ * Setting ATOM_PPLL_INVALID will cause SetPixelClock to skip
+ * PPLL/DCPLL programming and only program the DP DTO for the
+ * crtc virtual pixel clock.
+ */
if (atombios_get_encoder_mode(test_encoder) == ATOM_ENCODER_MODE_DP) {
- if (rdev->clock.dp_extclk)
+ if (ASIC_IS_DCE5(rdev) || rdev->clock.dp_extclk)
return ATOM_PPLL_INVALID;
}
}