Re: Regression: drm/radeon: brightness control hard system lockup

From: Alex Deucher
Date: Mon Jan 07 2013 - 10:20:39 EST

On Sun, Jan 6, 2013 at 7:59 AM, Eldad Zack <eldad@xxxxxxxxxxxxxxx> wrote:
> Hi Alex,
> Commit 0ecebb9e0d14e9948e0b1529883a776758117d6f "drm/radeon: switch to a
> finer grained reset for evergreen" introduced a hard system lockup to my
> setup. I found it after bisecting, and confirmed it by reverting it on
> the latest mainline ( 5f243b9 ).
> This:
> echo 7 > /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0/brightness
> Causes a hard lock-up hard, i.e. immediate freeze, without any logs.
> See lspci output and kernel .config below.
> If there's any more info I can provide, please let me know.

Do you normally see GPU resets when changing the backlight? Please
attach your dmesg output when changing the backlight with the patch

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