drm/radeon: don't use fractional dividers on RS[78]80 if SS is enabled
authorChristian König <christian.koenig@amd.com>
Mon, 13 Jun 2016 14:09:53 +0000 (16:09 +0200)
committerAlex Deucher <alexander.deucher@amd.com>
Mon, 13 Jun 2016 16:23:15 +0000 (12:23 -0400)
Seems to cause problems for some older hardware. Kudos to Thom Kouwenhoven
for working a lot with the PLLs and figuring this out.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/radeon/atombios_crtc.c

index 2e216e2ea78c3535a07b761327c04c345a6667ff..259cd6e6d71c3dc532c5aa4a65e64be040e151f7 100644 (file)
@@ -589,7 +589,8 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
                if (ASIC_IS_DCE41(rdev) || ASIC_IS_DCE61(rdev) || ASIC_IS_DCE8(rdev))
                        radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
                /* use frac fb div on RS780/RS880 */
-               if ((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
+               if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
+                   && !radeon_crtc->ss_enabled)
                        radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
                if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
                        radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
@@ -626,7 +627,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
                        if (radeon_crtc->ss.refdiv) {
                                radeon_crtc->pll_flags |= RADEON_PLL_USE_REF_DIV;
                                radeon_crtc->pll_reference_div = radeon_crtc->ss.refdiv;
-                               if (ASIC_IS_AVIVO(rdev))
+                               if (rdev->family >= CHIP_RV770)
                                        radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
                        }
                }