Date: Fri, 31 Aug 2018 16:16:20 +0000 (UTC)
From: Paul Sarraffe <psarraf@xxxxxxxxx>
To: "fedora-kernel-acpi@xxxxxxxxxxxxxxxxx"
Kernel update 4.17.19 broke the brightness control on my DELL Inspiron
N4010. It worked fine with kernel 4.17.18.
It appears that the following change fixed brightness control on some
DELL laptops while breaking it on others:
commit 587eb87b45bb6a97452b9719f63cd489e1371e77
Author: Damien Thébault <damien@xxxxxxxx>
Date: Wed Jul 18 12:06:01 2018 +0200
platform/x86: dell-laptop: Fix backlight detection
[ Upstream commit 2502e5a025935b7b476b69eda4959b3c4022c72b ]
Hello Paul,
The SMM refactoring change that this commit was intended to fix occured
between 4.14 and 4.15, do you have a way to check those kernel versions
?
This would allow to verify if it worked before the SMM refactoring.
I don't know this subject much, but the BIOS might be replying something
not expected in the code.
Are you connected to AC power during boot ?
Maybe utilities from the libsmbios project could allow to investigate
the issue ?
--
Damien Thébault
