[PATCH 5.16 05/37] drm/mgag200: Fix PLL setup for g200wb and g200ew

From: Greg Kroah-Hartman
Date: Mon Mar 21 2022 - 10:12:46 EST


From: Jocelyn Falempe <jfalempe@xxxxxxxxxx>

commit 40ce1121c1d76daf9048a86e36c83e469281b9fd upstream.

commit f86c3ed55920 ("drm/mgag200: Split PLL setup into compute and
update functions") introduced a regression for g200wb and g200ew.
The PLLs are not set up properly, and VGA screen stays
black, or displays "out of range" message.

MGA1064_WB_PIX_PLLC_N/M/P was mistakenly replaced with
MGA1064_PIX_PLLC_N/M/P which have different addresses.

Patch tested on a Dell T310 with g200wb

Fixes: f86c3ed55920 ("drm/mgag200: Split PLL setup into compute and update functions")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220308174321.225606-1-jfalempe@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/mgag200/mgag200_pll.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/mgag200/mgag200_pll.c
+++ b/drivers/gpu/drm/mgag200/mgag200_pll.c
@@ -404,9 +404,9 @@ mgag200_pixpll_update_g200wb(struct mgag
udelay(50);

/* program pixel pll register */
- WREG_DAC(MGA1064_PIX_PLLC_N, xpixpllcn);
- WREG_DAC(MGA1064_PIX_PLLC_M, xpixpllcm);
- WREG_DAC(MGA1064_PIX_PLLC_P, xpixpllcp);
+ WREG_DAC(MGA1064_WB_PIX_PLLC_N, xpixpllcn);
+ WREG_DAC(MGA1064_WB_PIX_PLLC_M, xpixpllcm);
+ WREG_DAC(MGA1064_WB_PIX_PLLC_P, xpixpllcp);

udelay(50);