Hi, On 2024-08-01 10:52:55+0000, Hans de Goede wrote: > On 7/31/24 10:55 PM, Daniel Vetter wrote: > > On Wed, Jul 31, 2024 at 08:40:12PM +0300, Jani Nikula wrote: > >> On Wed, 31 Jul 2024, Thomas Weißschuh <linux@xxxxxxxxxxxxxx> wrote: > >>> The value of "min_input_signal" returned from ATIF on a Framework AMD 13 > >>> is "12". This leads to a fairly bright minimum display backlight. > >>> > >>> Add a generic override helper for the user to override the settings > >>> provided by the firmware through the kernel cmdline. > >>> Also add amdgpu as a user of that helper. > >>> > >>> One solution would be a fixed firmware version, which was announced but > >>> has no timeline. > >> > >> The flip side is that if we add this now, it pretty much has a timeline: > >> We'll have to carry and support it forever. > >> > >> It's not a great prospect for something so specific. Not to mention that > >> the limits are generally there for electrical minimums that should not > >> be overridden. And before you know it, we'll have bug reports about > >> flickering screens... > > > > Yeah I think for this specific case where a fixed firmware is already > > kinda promised, a quirk is the right fix. Otherwise we open up a can of > > worms here ... so personally I like v2 a lot more. > > -Sima > > Ok, with both Jani and Sima preferring the quirk approach from v2, > I withdraw my objection against v2. So lets go with that version. Ack. I want to note though, that there are enough other commandline options that can mess things up. An invalid video=MODELINE, custom ACPI tables, etc, so the fallout from the new commandline variable doesn't seem too bad to me. > Thomas, sorry about this. No worries! > I see that other then a remark from Jeff Johnson about a missing > MODULE_DESCRIPTION() v2 does not have any reviews yet though. > > So we will need to review that version now. Might be best for > visibility of the patches in people's review queue to repost > v2 as v4 with the MODULE_DESCRIPTION() fixed ? I can do that. > > >>> This helper does conflict with the mode override via the cmdline. > >>> Only one can be specified. > >>> IMO the mode override can be extended to also handle "min-brightness" > >>> when that becomes necessary. > >>> > >>> --- > >>> Changes in v3: > >>> - Switch to cmdline override parameter > >>> - Link to v2: https://lore.kernel.org/r/20240623-amdgpu-min-backlight-quirk-v2-0-cecf7f49da9b@xxxxxxxxxxxxxx > >>> > >>> Changes in v2: > >>> - Introduce proper drm backlight quirk infrastructure > >>> - Quirk by EDID and DMI instead of only DMI > >>> - Limit quirk to only single Framework 13 matte panel > >>> - Link to v1: https://lore.kernel.org/r/20240610-amdgpu-min-backlight-quirk-v1-1-8459895a5b2a@xxxxxxxxxxxxxx > >>> > >>> --- > >>> Thomas Weißschuh (2): > >>> drm/connector: add drm_connector_get_cmdline_min_brightness_override() > >>> drm/amd/display: implement minimum brightness override > >>> > >>> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 ++++ > >>> drivers/gpu/drm/drm_connector.c | 34 +++++++++++++++++++++++ > >>> include/drm/drm_connector.h | 2 ++ > >>> 3 files changed, 42 insertions(+) > >>> --- > >>> base-commit: 36821612eb3091a21f7f4a907b497064725080c3 > >>> change-id: 20240610-amdgpu-min-backlight-quirk-8402fd8e736a > >>> > >>> Best regards, > >> > >> -- > >> Jani Nikula, Intel > > >
