[Public] Hi Samuel, Can you please try: https://patchwork.freedesktop.org/patch/463485/ ? Thanks, Roman > -----Original Message----- > From: Samuel Čavoj <samuel@xxxxxxxxx> > Sent: Tuesday, November 16, 2021 8:33 AM > To: Alex Deucher <alexdeucher@xxxxxxxxx> > Cc: Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Li, Sun peng (Leo) > <Sunpeng.Li@xxxxxxx>; Li, Roman <Roman.Li@xxxxxxx>; Maling list - DRI > developers <dri-devel@xxxxxxxxxxxxxxxxxxxxx>; LKML <linux- > kernel@xxxxxxxxxxxxxxx>; amd-gfx list <amd-gfx@xxxxxxxxxxxxxxxxxxxxx> > Subject: Re: Backlight control broken on UM325 (OLED) on 5.15 (bisected) > > Hi Alex, > > thank you for your response. > > On 15.11.2021 10:43, Alex Deucher wrote: > > [...] > > > > That patch adds support for systems with multiple backlights. Do you > > have multiple backlight devices now? If so, does the other one work? > > No, there is still only one backlight device -- amdgpu_bl0. > > > > Can you also try this patch? > > > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c > > b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c > > index 4811b0faafd9..67163c9d49e6 100644 > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c > > @@ -854,8 +854,8 @@ int amdgpu_acpi_init(struct amdgpu_device *adev) > > if (amdgpu_device_has_dc_support(adev)) { #if > > defined(CONFIG_DRM_AMD_DC) > > struct amdgpu_display_manager *dm = &adev->dm; > > - if (dm->backlight_dev[0]) > > - atif->bd = dm->backlight_dev[0]; > > + if (dm->backlight_dev[1]) > > + atif->bd = dm->backlight_dev[1]; > > #endif > > } else { > > struct drm_encoder *tmp; > > > > There is no difference in behaviour after applying the patch. > > Samuel > > > > > Alex > > > > > > > > Regards, > > > Samuel Čavoj > > > > > > [0]: > > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fww > > > > w.reddit.com%2Fr%2FAMDLaptops%2Fcomments%2Fqst0fm%2Fafter_updating > _t > > > > o_linux_515_my_brightness%2F&data=04%7C01%7CRoman.Li%40amd.co > m%7 > > > > Ce1c766a2f7014cdb664308d9a9059cc6%7C3dd8961fe4884e608e11a82d994e1 > 83d > > > > %7C0%7C0%7C637726663861883494%7CUnknown%7CTWFpbGZsb3d8eyJWIjoi > MC4wLj > > > > AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&s > dat > > > > a=hfsaEzng9%2FjAI2F%2BKg87Tv2Mu%2FfPurCQELr62%2B%2FVF%2BQ%3D&a > mp;res > > > erved=0