* [REGRESSION][BISECTED] 5.9-rc4 disables console on radeon
@ 2020-09-08 16:27 ` Mikael Pettersson
0 siblings, 0 replies; 4+ messages in thread
From: Mikael Pettersson @ 2020-09-08 16:27 UTC (permalink / raw)
To: Linux Kernel list, amd-gfx, Kai-Heng Feng
Starting with linux-5.9-rc4, the Dell monitor on my desktop PC goes
black during boot
when the kernel activates the framebuffer console, except for this
error message shown
in the center of the screen:
"Dell U2412M
The current input timing is not supported by the monitor display. Please
change your input timing to 1920x1200@60Hz or any other monitor
listed timing as per the monitor specifications.
<DVI symbol>"
The monitor remains black until I reboot.
All kernels up to and including 5.9-rc3 were Ok. A git bisect identified
# first bad commit: [fc8c70526bd30733ea8667adb8b8ffebea30a8ed]
drm/radeon: Prefer lower feedback dividers
as the culprit, and reverting that from -rc4 makes the console work again.
Adding a bit of debugging code to that function shows:
avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
avivo_get_fb_ref_div: fb_div_new 142 fb_div_old 143
avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
avivo_get_fb_ref_div: fb_div_new 119 fb_div_old 120
avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
during boot, where "new" is what the commit above changed the code to compute,
and "old" is the value computed by the working code from rc3.
The graphics card is a Radeon HD6450 silent model:
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc.
[AMD/ATI] Caicos [Radeon HD 6450/7450/8450 / R5 230 OEM] (prog-if 00
[VGA controller])
^ permalink raw reply [flat|nested] 4+ messages in thread
* [REGRESSION][BISECTED] 5.9-rc4 disables console on radeon
@ 2020-09-08 16:27 ` Mikael Pettersson
0 siblings, 0 replies; 4+ messages in thread
From: Mikael Pettersson @ 2020-09-08 16:27 UTC (permalink / raw)
To: Linux Kernel list, amd-gfx, Kai-Heng Feng
Starting with linux-5.9-rc4, the Dell monitor on my desktop PC goes
black during boot
when the kernel activates the framebuffer console, except for this
error message shown
in the center of the screen:
"Dell U2412M
The current input timing is not supported by the monitor display. Please
change your input timing to 1920x1200@60Hz or any other monitor
listed timing as per the monitor specifications.
<DVI symbol>"
The monitor remains black until I reboot.
All kernels up to and including 5.9-rc3 were Ok. A git bisect identified
# first bad commit: [fc8c70526bd30733ea8667adb8b8ffebea30a8ed]
drm/radeon: Prefer lower feedback dividers
as the culprit, and reverting that from -rc4 makes the console work again.
Adding a bit of debugging code to that function shows:
avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
avivo_get_fb_ref_div: fb_div_new 142 fb_div_old 143
avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
avivo_get_fb_ref_div: fb_div_new 119 fb_div_old 120
avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
during boot, where "new" is what the commit above changed the code to compute,
and "old" is the value computed by the working code from rc3.
The graphics card is a Radeon HD6450 silent model:
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc.
[AMD/ATI] Caicos [Radeon HD 6450/7450/8450 / R5 230 OEM] (prog-if 00
[VGA controller])
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [REGRESSION][BISECTED] 5.9-rc4 disables console on radeon
2020-09-08 16:27 ` Mikael Pettersson
@ 2020-09-09 9:15 ` Christian König
-1 siblings, 0 replies; 4+ messages in thread
From: Christian König @ 2020-09-09 9:15 UTC (permalink / raw)
To: Mikael Pettersson, Linux Kernel list, amd-gfx, Kai-Heng Feng
Yes, that is an already known issue.
We are most likely going to revert the patch ASAP.
Christian.
Am 08.09.20 um 18:27 schrieb Mikael Pettersson:
> Starting with linux-5.9-rc4, the Dell monitor on my desktop PC goes
> black during boot
> when the kernel activates the framebuffer console, except for this
> error message shown
> in the center of the screen:
>
> "Dell U2412M
> The current input timing is not supported by the monitor display. Please
> change your input timing to 1920x1200@60Hz or any other monitor
> listed timing as per the monitor specifications.
> <DVI symbol>"
>
> The monitor remains black until I reboot.
>
> All kernels up to and including 5.9-rc3 were Ok. A git bisect identified
>
> # first bad commit: [fc8c70526bd30733ea8667adb8b8ffebea30a8ed]
> drm/radeon: Prefer lower feedback dividers
>
> as the culprit, and reverting that from -rc4 makes the console work again.
>
> Adding a bit of debugging code to that function shows:
>
> avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
> avivo_get_fb_ref_div: fb_div_new 142 fb_div_old 143
> avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
> avivo_get_fb_ref_div: fb_div_new 119 fb_div_old 120
> avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
>
> during boot, where "new" is what the commit above changed the code to compute,
> and "old" is the value computed by the working code from rc3.
>
> The graphics card is a Radeon HD6450 silent model:
> 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc.
> [AMD/ATI] Caicos [Radeon HD 6450/7450/8450 / R5 230 OEM] (prog-if 00
> [VGA controller])
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [REGRESSION][BISECTED] 5.9-rc4 disables console on radeon
@ 2020-09-09 9:15 ` Christian König
0 siblings, 0 replies; 4+ messages in thread
From: Christian König @ 2020-09-09 9:15 UTC (permalink / raw)
To: Mikael Pettersson, Linux Kernel list, amd-gfx, Kai-Heng Feng
Yes, that is an already known issue.
We are most likely going to revert the patch ASAP.
Christian.
Am 08.09.20 um 18:27 schrieb Mikael Pettersson:
> Starting with linux-5.9-rc4, the Dell monitor on my desktop PC goes
> black during boot
> when the kernel activates the framebuffer console, except for this
> error message shown
> in the center of the screen:
>
> "Dell U2412M
> The current input timing is not supported by the monitor display. Please
> change your input timing to 1920x1200@60Hz or any other monitor
> listed timing as per the monitor specifications.
> <DVI symbol>"
>
> The monitor remains black until I reboot.
>
> All kernels up to and including 5.9-rc3 were Ok. A git bisect identified
>
> # first bad commit: [fc8c70526bd30733ea8667adb8b8ffebea30a8ed]
> drm/radeon: Prefer lower feedback dividers
>
> as the culprit, and reverting that from -rc4 makes the console work again.
>
> Adding a bit of debugging code to that function shows:
>
> avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
> avivo_get_fb_ref_div: fb_div_new 142 fb_div_old 143
> avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
> avivo_get_fb_ref_div: fb_div_new 119 fb_div_old 120
> avivo_get_fb_ref_div: fb_div_new 136 fb_div_old 137
>
> during boot, where "new" is what the commit above changed the code to compute,
> and "old" is the value computed by the working code from rc3.
>
> The graphics card is a Radeon HD6450 silent model:
> 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc.
> [AMD/ATI] Caicos [Radeon HD 6450/7450/8450 / R5 230 OEM] (prog-if 00
> [VGA controller])
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-09-09 9:15 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-09-08 16:27 [REGRESSION][BISECTED] 5.9-rc4 disables console on radeon Mikael Pettersson
2020-09-08 16:27 ` Mikael Pettersson
2020-09-09 9:15 ` Christian König
2020-09-09 9:15 ` Christian König
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