drm/radeon/kms: pll tweaks for rv6xx

Prefer minm over maxp.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=35994

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index b41ec59c7100..9d516a8c4dfa 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -531,6 +531,12 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
                         pll->flags |= RADEON_PLL_PREFER_HIGH_FB_DIV;
                 else
                         pll->flags |= RADEON_PLL_PREFER_LOW_REF_DIV;
+
+                if ((rdev->family == CHIP_R600) ||
+                    (rdev->family == CHIP_RV610) ||
+                    (rdev->family == CHIP_RV630) ||
+                    (rdev->family == CHIP_RV670))
+                        pll->flags |= RADEON_PLL_PREFER_MINM_OVER_MAXP;
         } else {
                 pll->flags |= RADEON_PLL_LEGACY;