drm/radeon/kms: more r4xx lvds fixes

Grab pll ref div from regs at driver init.  r4xx seems very
picky about the dividers for the pll driving lvds.

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

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_clocks.c b/drivers/gpu/drm/radeon/radeon_clocks.c
index 2c541e08f160..b062109efbee 100644
--- a/drivers/gpu/drm/radeon/radeon_clocks.c
+++ b/drivers/gpu/drm/radeon/radeon_clocks.c
@@ -106,8 +106,19 @@ void radeon_get_clock_info(struct drm_device *dev)
                 ret = radeon_combios_get_clock_info(dev);
 
         if (ret) {
-                if (p1pll->reference_div < 2)
-                        p1pll->reference_div = 12;
+                if (p1pll->reference_div < 2) {
+                        if (!ASIC_IS_AVIVO(rdev)) {
+                                u32 tmp = RREG32_PLL(RADEON_PPLL_REF_DIV);
+                                if (ASIC_IS_R300(rdev))
+                                        p1pll->reference_div =
+                                                (tmp & R300_PPLL_REF_DIV_ACC_MASK) >> R300_PPLL_REF_DIV_ACC_SHIFT;
+                                else
+                                        p1pll->reference_div = tmp & RADEON_PPLL_REF_DIV_MASK;
+                                if (p1pll->reference_div < 2)
+                                        p1pll->reference_div = 12;
+                        } else
+                                p1pll->reference_div = 12;
+                }
                 if (p2pll->reference_div < 2)
                         p2pll->reference_div = 12;
                 if (rdev->family < CHIP_RS600) {