drm/radeon: don't disable plls that are in use by other crtcs

Some plls are shared for DP.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index f4d4505fe831..961d366f00eb 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -1682,9 +1682,22 @@ static void atombios_crtc_disable(struct drm_crtc *crtc)
         struct drm_device *dev = crtc->dev;
         struct radeon_device *rdev = dev->dev_private;
         struct radeon_atom_ss ss;
+        int i;
 
         atombios_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
 
+        for (i = 0; i < rdev->num_crtc; i++) {
+                if (rdev->mode_info.crtcs[i] &&
+                    rdev->mode_info.crtcs[i]->enabled &&
+                    i != radeon_crtc->crtc_id &&
+                    radeon_crtc->pll_id == rdev->mode_info.crtcs[i]->pll_id) {
+                        /* one other crtc is using this pll don't turn
+                         * off the pll
+                         */
+                        goto done;
+                }
+        }
+
         switch (radeon_crtc->pll_id) {
         case ATOM_PPLL1:
         case ATOM_PPLL2:
@@ -1701,6 +1714,7 @@ static void atombios_crtc_disable(struct drm_crtc *crtc)
         default:
                 break;
         }
+done:
         radeon_crtc->pll_id = -1;
 }