drm/radeon/dce3: switch back to old pll allocation order for discrete

The order shouldn't matter, but this seems to cause regressions for
certain specific cases.  This should fix it for now.  We probably
need to investigate a proper fix in the next development cycle.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Andy Furniss <andyqos@ukfsn.org>

drivers/gpu/drm/radeon/atombios_crtc.c

@@ -1696,35 +1696,43 @@ static int radeon_atom_pick_pll(struct drm_crtc *crtc)
 			return ATOM_PPLL2;
 		DRM_ERROR("unable to allocate a PPLL\n");
 		return ATOM_PPLL_INVALID;
-	} else {
-		if (ASIC_IS_AVIVO(rdev)) {
-			/* in DP mode, the DP ref clock can come from either PPLL
-			 * depending on the asic:
-			 * DCE3: PPLL1 or PPLL2
-			 */
-			if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(radeon_crtc->encoder))) {
-				/* use the same PPLL for all DP monitors */
-				pll = radeon_get_shared_dp_ppll(crtc);
-				if (pll != ATOM_PPLL_INVALID)
-					return pll;
-			} else {
-				/* use the same PPLL for all monitors with the same clock */
-				pll = radeon_get_shared_nondp_ppll(crtc);
-				if (pll != ATOM_PPLL_INVALID)
-					return pll;
-			}
-			/* all other cases */
-			pll_in_use = radeon_get_pll_use_mask(crtc);
+	} else if (ASIC_IS_AVIVO(rdev)) {
+		/* in DP mode, the DP ref clock can come from either PPLL
+		 * depending on the asic:
+		 * DCE3: PPLL1 or PPLL2
+		 */
+		if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(radeon_crtc->encoder))) {
+			/* use the same PPLL for all DP monitors */
+			pll = radeon_get_shared_dp_ppll(crtc);
+			if (pll != ATOM_PPLL_INVALID)
+				return pll;
+		} else {
+			/* use the same PPLL for all monitors with the same clock */
+			pll = radeon_get_shared_nondp_ppll(crtc);
+			if (pll != ATOM_PPLL_INVALID)
+				return pll;
+		}
+		/* all other cases */
+		pll_in_use = radeon_get_pll_use_mask(crtc);
+		/* the order shouldn't matter here, but we probably
+		 * need this until we have atomic modeset
+		 */
+		if (rdev->flags & RADEON_IS_IGP) {
 			if (!(pll_in_use & (1 << ATOM_PPLL1)))
 				return ATOM_PPLL1;
 			if (!(pll_in_use & (1 << ATOM_PPLL2)))
 				return ATOM_PPLL2;
-			DRM_ERROR("unable to allocate a PPLL\n");
-			return ATOM_PPLL_INVALID;
 		} else {
-			/* on pre-R5xx asics, the crtc to pll mapping is hardcoded */
-			return radeon_crtc->crtc_id;
+			if (!(pll_in_use & (1 << ATOM_PPLL2)))
+				return ATOM_PPLL2;
+			if (!(pll_in_use & (1 << ATOM_PPLL1)))
+				return ATOM_PPLL1;
 		}
+		DRM_ERROR("unable to allocate a PPLL\n");
+		return ATOM_PPLL_INVALID;
+	} else {
+		/* on pre-R5xx asics, the crtc to pll mapping is hardcoded */
+		return radeon_crtc->crtc_id;
 	}
 }