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| author | Jocelyn Falempe <jfalempe@redhat.com> | 2022-10-13 15:28:10 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-12 12:00:49 +0100 |
| commit | 99f08ff40c4b34a39ab47960f80512c7806953a7 (patch) | |
| tree | 722f52df7cbc14085a0bc36c4fcb6b55472f9ad9 | |
| parent | df201eb96a98e04d07abb419b3bf9222546e3831 (diff) | |
| download | linux-stable-99f08ff40c4b34a39ab47960f80512c7806953a7.tar.gz linux-stable-99f08ff40c4b34a39ab47960f80512c7806953a7.tar.bz2 linux-stable-99f08ff40c4b34a39ab47960f80512c7806953a7.zip | |
drm/mgag200: Fix PLL setup for G200_SE_A rev >=4
commit b389286d0234e1edbaf62ed8bc0892a568c33662 upstream.
For G200_SE_A, PLL M setting is wrong, which leads to blank screen,
or "signal out of range" on VGA display.
previous code had "m |= 0x80" which was changed to
m |= ((pixpllcn & BIT(8)) >> 1);
Tested on G200_SE_A rev 42
This line of code was moved to another file with
commit 877507bb954e ("drm/mgag200: Provide per-device callbacks for
PIXPLLC") but can be easily backported before this commit.
v2: * put BIT(7) First to respect MSB-to-LSB (Thomas)
* Add a comment to explain that this bit must be set (Thomas)
Fixes: 2dd040946ecf ("drm/mgag200: Store values (not bits) in struct mgag200_pll_values")
Cc: stable@vger.kernel.org
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20221013132810.521945-1-jfalempe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/gpu/drm/mgag200/mgag200_pll.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/gpu/drm/mgag200/mgag200_pll.c b/drivers/gpu/drm/mgag200/mgag200_pll.c index 8065ca5d8de9..4f55961848a8 100644 --- a/drivers/gpu/drm/mgag200/mgag200_pll.c +++ b/drivers/gpu/drm/mgag200/mgag200_pll.c @@ -269,7 +269,8 @@ static void mgag200_pixpll_update_g200se_04(struct mgag200_pll *pixpll, pixpllcp = pixpllc->p - 1; pixpllcs = pixpllc->s; - xpixpllcm = pixpllcm | ((pixpllcn & BIT(8)) >> 1); + // For G200SE A, BIT(7) should be set unconditionally. + xpixpllcm = BIT(7) | pixpllcm; xpixpllcn = pixpllcn; xpixpllcp = (pixpllcs << 3) | pixpllcp; |