This is a note to let you know that I've just added the patch titled
drm/mgag200: Bug fix: Modified pll algorithm for EH project
to the 3.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-mgag200-bug-fix-modified-pll-algorithm-for-eh-project.patch
and it can be found in the queue-3.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 260b3f1291a75a580d22ce8bfb1499c617272716 Mon Sep 17 00:00:00 2001
From: Julia Lemire <jlemire@xxxxxxxxxx>
Date: Mon, 18 Mar 2013 10:17:47 -0400
Subject: drm/mgag200: Bug fix: Modified pll algorithm for EH project
From: Julia Lemire <jlemire@xxxxxxxxxx>
commit 260b3f1291a75a580d22ce8bfb1499c617272716 upstream.
While testing the mgag200 kms driver on the HP ProLiant Gen8, a
bug was seen. Once the bootloader would load the selected kernel,
the screen would go black. At first it was assumed that the
mgag200 kms driver was hanging. But after setting up the grub
serial output, it was seen that the driver was being loaded
properly. After trying serval monitors, one finaly displayed
the message "Frequency Out of Range". By comparing the kms pll
algorithm with the previous mgag200 xorg driver pll algorithm,
discrepencies were found. Once the kms pll algorithm was
modified, the expected pll values were produced. This fix was
tested on several monitors of varying native resolutions.
Signed-off-by: Julia Lemire <jlemire@xxxxxxxxxx>
Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/mgag200/mgag200_mode.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -382,19 +382,19 @@ static int mga_g200eh_set_plls(struct mg
m = n = p = 0;
vcomax = 800000;
vcomin = 400000;
- pllreffreq = 3333;
+ pllreffreq = 33333;
delta = 0xffffffff;
permitteddelta = clock * 5 / 1000;
- for (testp = 16; testp > 0; testp--) {
+ for (testp = 16; testp > 0; testp >>= 1) {
if (clock * testp > vcomax)
continue;
if (clock * testp < vcomin)
continue;
for (testm = 1; testm < 33; testm++) {
- for (testn = 1; testn < 257; testn++) {
+ for (testn = 17; testn < 257; testn++) {
computed = (pllreffreq * testn) /
(testm * testp);
if (computed > clock)
@@ -404,11 +404,11 @@ static int mga_g200eh_set_plls(struct mg
if (tmpdelta < delta) {
delta = tmpdelta;
n = testn - 1;
- m = (testm - 1) | ((n >> 1) & 0x80);
+ m = (testm - 1);
p = testp - 1;
}
if ((clock * testp) >= 600000)
- p |= 80;
+ p |= 0x80;
}
}
}
Patches currently in stable-queue which might be from jlemire@xxxxxxxxxx are
queue-3.8/drm-mgag200-bug-fix-modified-pll-algorithm-for-eh-project.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html