drm/radeon: validate PPLL in crtc fixup

This allows us to bail if we can't support the requested
setup from a PPLL perspective.  Prevents broken setups
from being attempted.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 8e32c5891be1..96184d02c8d9 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -1810,6 +1810,13 @@ static bool atombios_crtc_mode_fixup(struct drm_crtc *crtc,
                 return false;
         if (!atombios_crtc_prepare_pll(crtc, adjusted_mode))
                 return false;
+        /* pick pll */
+        radeon_crtc->pll_id = radeon_atom_pick_pll(crtc);
+        /* if we can't get a PPLL for a non-DP encoder, fail */
+        if ((radeon_crtc->pll_id == ATOM_PPLL_INVALID) &&
+            !ENCODER_MODE_IS_DP(atombios_get_encoder_mode(radeon_crtc->encoder)))
+                return false;
+
         return true;
 }
 
@@ -1820,8 +1827,6 @@ static void atombios_crtc_prepare(struct drm_crtc *crtc)
         struct radeon_device *rdev = dev->dev_private;
 
         radeon_crtc->in_mode_set = true;
-        /* pick pll */
-        radeon_crtc->pll_id = radeon_atom_pick_pll(crtc);
 
         /* disable crtc pair power gating before programming */
         if (ASIC_IS_DCE6(rdev))