On 2020-05-20 6:03 p.m., Koo, Anthony wrote: > [AMD Official Use Only - Internal Distribution Only] > > Hi Harry, > > It does sound like a firmware issue. > I think we will need to do some investigation here. I would be curious if this is a driver regression or just never worked (not sure how new the driver being tested is). > > This point below seems to indicate the firmware might be using some uninitialized values in some if its calculations. > Typically these value would be things like backlight characteristic curves that are passed to the firmware via a table generated in the power helpers file, and programmed in our dc code. Do you think this could be related to Wyatt's endian-ness fixes? Harry > I'm not 100% sure this is the problem, but it could be something we can take a look at from dmcu_load_iram. >>> There's a bugreport on the tracker from a person with the same laptop >>> model as mine that says that the threshold may vary from boot to boot. > > Thanks, > Anthony > > -----Original Message----- > From: Wentland, Harry <Harry.Wentland@xxxxxxx> > Sent: Wednesday, May 20, 2020 5:53 PM > To: Alex Deucher <alexdeucher@xxxxxxxxx>; Alexander Monakov <amonakov@xxxxxxxxx>; Kazlauskas, Nicholas <Nicholas.Kazlauskas@xxxxxxx>; Li, Sun peng (Leo) <Sunpeng.Li@xxxxxxx> > Cc: amd-gfx list <amd-gfx@xxxxxxxxxxxxxxxxxxxxx>; Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Chiu, Michael <Michael.Chiu@xxxxxxx>; Koo, Anthony <Anthony.Koo@xxxxxxx> > Subject: Re: Flaky brightness on Renoir > > We've seen similar problems internally. > > Michael, does this "fix" your issue? > > Anthony, looks like smooth_brightness is problematic on (some) renoir systems. Thoughts? > > Thanks, > Harry > > On 2020-05-20 5:47 p.m., Alex Deucher wrote: >> Adding some display people. >> >> On Wed, May 20, 2020 at 5:46 PM Alexander Monakov <amonakov@xxxxxxxxx> wrote: >>> >>> Hello, >>> >>> I have a laptop with the recent Renoir SoC. Screen brightness is >>> controlled via the amdgpu driver. Unfortunately it doesn't work >>> properly: brightness doesn't go below a certain threshold. In one >>> experiment I've found the threshold to be about 95 (of 255), which is >>> quite high. >>> >>> There's a bugreport on the tracker from a person with the same laptop >>> model as mine that says that the threshold may vary from boot to boot. >>> >>> So far I was able to find a workaround: avoiding >>> dmcu_set_backlight_level like in the patch below gives more reliable >>> backlight control (but at the expense of breaking "actual_brightness" >>> sysfs file, because it reads from DMCU registers). >>> >>> What might be the problem and can I help investigate this further? >>> Would really like to see this work properly. >>> >>> Alexander >>> >>> diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c >>> b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c >>> index b8a3fc505c9b..3274b0d15893 100644 >>> --- a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c >>> +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c >>> @@ -428,7 +428,7 @@ static bool dce_abm_set_backlight_level_pwm( >>> backlight_pwm_u16_16, backlight_pwm_u16_16); >>> >>> /* If DMCU is in reset state, DMCU is uninitialized */ >>> - if (use_smooth_brightness) >>> + if (0 && use_smooth_brightness) >>> dmcu_set_backlight_level(abm_dce, >>> backlight_pwm_u16_16, >>> frame_ramp, >>> _______________________________________________ >>> amd-gfx mailing list >>> amd-gfx@xxxxxxxxxxxxxxxxxxxxx >>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
