amd64/181357: LCD Brightness Control not working on Lenovo X121e (ACPI issue?)
matthias at petermann-it.de
Sat Aug 24 15:20:02 UTC 2013
The following reply was made to PR amd64/181357; it has been noted by GNATS.
From: Matthias Petermann <matthias at petermann-it.de>
To: bug-followup at FreeBSD.org, matthias at petermann-it.de,
current at freebsd.org
Subject: Re: amd64/181357: LCD Brightness Control not working on Lenovo X121e
Date: Sat, 24 Aug 2013 17:08:25 +0200
regarding this PR I made some further observation. Even the
acpi_ec_write seems to not have any effect on the brightness, the values
set to the appropriate register (IBM_EC_BRIGHTNESS 0x31) survive a
Looks like the values are stored correctly, but EC doesn't care for them
when setting brightness?
I'm not sure where to look next. Could this be a hardware issue with the
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