Date: Wed, 10 Feb 2021 09:15:00 -0800 From: Pete Wright <pete@nomadlogic.org> To: Kevin Oberman <rkoberman@gmail.com>, "freebsd-questions@freebsd.org" <questions@freebsd.org> Subject: Re: Brightness cannot be set on Lenovo L15 ThinkPad Message-ID: <220cabf0-14ce-88b6-fc33-14c650607e1b@nomadlogic.org> In-Reply-To: <CAN6yY1u4FAQ6GNFQ46hWxrOiUThRJjLnBJrNUwXdRAbidksx8g@mail.gmail.com> References: <CAN6yY1u4FAQ6GNFQ46hWxrOiUThRJjLnBJrNUwXdRAbidksx8g@mail.gmail.com>
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On 2/9/21 9:31 PM, Kevin Oberman wrote: > I can only guess that this may be an ACPI issue. > > I recently (last week) replaced my decade old T520 with a new ThinkPad L15 > with a 10th gen I5 CPU (Tiger Lake). I have everything working except the > WiFi (which I knew would not work) and setting brightness on the display. > > I have loaded acpi_ibm and it returns '0' for brightness. I tried > intel-backlight, which shows the brightness to be '0'. It does nothing, > either. > > I thought that I read that drm-fbsd13-kmod had the ability to do the job, > but I have no idea how to do anything with it. I do see sysctls for > hw.i915kms.enable_dpcd_backlight and invert_brightness, but I still have no > clue whether they are relevant. > > Any suggestions would be greatly appreciated! Hey there Kevin, I have a Thinkpad P43s with working backlight - on my end I load the both the acpi_ibm and acpi_video kernel modules. One interesting nit is that I have to load the ibm kmod *before* the video kmod or things don't work. Here's my kld_list from rc.conf: kld_list="cpuctl /boot/modules/i915kms.ko acpi_ibm acpi_video filemon" i also set my default brightness via sysctl.conf like so: hw.acpi.video.lcd0.brightness=40 My reading of the man pages is that acpi_ibm is used to enable the function keys to control brightness, volume control etc and acpi_video does manages the backlight brightness itself. Hope this helps, -pete -- Pete Wright pete@nomadlogic.org @nomadlogicLA
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