drm/mgag200: Black screen fix for G200e rev 4

- Fixed black screen for some resolutions of G200e rev4
- Fixed testm & testn which had predetermined value.

Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Mathieu Larouche <mathieu.larouche@matrox.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 14e64e08909ed1769e39d88d3a10124bfe2c2a2a..d347dca17267eca63c60cff0df63b5e854333dc9 100644 (file)
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -182,7 +182,7 @@ static int mga_g200se_set_plls(struct mga_device *mdev, long clock)
                        }
                }
 
-               fvv = pllreffreq * testn / testm;
+               fvv = pllreffreq * (n + 1) / (m + 1);
                fvv = (fvv - 800000) / 50000;
 
                if (fvv > 15)
@@ -202,6 +202,14 @@ static int mga_g200se_set_plls(struct mga_device *mdev, long clock)
        WREG_DAC(MGA1064_PIX_PLLC_M, m);
        WREG_DAC(MGA1064_PIX_PLLC_N, n);
        WREG_DAC(MGA1064_PIX_PLLC_P, p);
+
+       if (mdev->unique_rev_id >= 0x04) {
+               WREG_DAC(0x1a, 0x09);
+               msleep(20);
+               WREG_DAC(0x1a, 0x01);
+
+       }
+
        return 0;
 }