Created attachment 146015 [details] VBIOS Filing this at the request of some of the Intel folks. I recently got my hand on a ThinkPad X1 Extreme 2nd Generation with the optional 4K AMOLED screen, and discovered that backlight controls weren't working. While there seems to be multiple problems here, all of which I've come up with some patches for that I plan to send out after filing this bug, one of the big things I noticed was that despite requiring DPCD backlight control this laptop claims to be using PWM backlight controls in it's vbios. So, I'm filing this bug to upload the vbios along with DPCD and other relevant information here. As well, here's a dump of some relevant DPCD registers: [ 3.142168] [drm:intel_dp_read_dpcd [i915]] DPCD: 14 14 c4 01 00 00 01 c0 02 14 00 00 00 08 82 [ 3.142600] [drm:drm_dp_read_desc [drm_kms_helper]] DP sink: OUI ba-41-59 dev-ID HW-rev 0.0 SW-rev 0.0 quirks 0x0000 [ 3.143012] [drm:intel_dp_init_connector [i915]] eDP DPCD: 05 9d a6 If you need any more information just let me know and I'll be happy to uplaod it
(In reply to Lyude Paul from comment #0) > Created attachment 146015 [details] > VBIOS > > Filing this at the request of some of the Intel folks. I recently got my > hand on a ThinkPad X1 Extreme 2nd Generation with the optional 4K AMOLED > screen, and discovered that backlight controls weren't working. While there > seems to be multiple problems here, all of which I've come up with some > patches for that I plan to send out after filing this bug, one of the big > things I noticed was that despite requiring DPCD backlight control this > laptop claims to be using PWM backlight controls in it's vbios. So, I'm > filing this bug to upload the vbios along with DPCD and other relevant > information here. > > As well, here's a dump of some relevant DPCD registers: > > [ 3.142168] [drm:intel_dp_read_dpcd [i915]] DPCD: 14 14 c4 01 00 00 01 c0 > 02 14 00 00 00 08 82 > [ 3.142600] [drm:drm_dp_read_desc [drm_kms_helper]] DP sink: OUI ba-41-59 > dev-ID HW-rev 0.0 SW-rev 0.0 quirks 0x0000 > [ 3.143012] [drm:intel_dp_init_connector [i915]] eDP DPCD: 05 9d a6 > > If you need any more information just let me know and I'll be happy to > uplaod it How old is the kernel? Can you attach the full dmesg with kernel parameters drm.debug=0x1e log_buf_len=4M to see more information about the issue?
(In reply to Lakshmi from comment #1) > (In reply to Lyude Paul from comment #0) > > Created attachment 146015 [details] > > VBIOS > > > > Filing this at the request of some of the Intel folks. I recently got my > > hand on a ThinkPad X1 Extreme 2nd Generation with the optional 4K AMOLED > > screen, and discovered that backlight controls weren't working. While there > > seems to be multiple problems here, all of which I've come up with some > > patches for that I plan to send out after filing this bug, one of the big > > things I noticed was that despite requiring DPCD backlight control this > > laptop claims to be using PWM backlight controls in it's vbios. So, I'm > > filing this bug to upload the vbios along with DPCD and other relevant > > information here. > > > > As well, here's a dump of some relevant DPCD registers: > > > > [ 3.142168] [drm:intel_dp_read_dpcd [i915]] DPCD: 14 14 c4 01 00 00 01 c0 > > 02 14 00 00 00 08 82 > > [ 3.142600] [drm:drm_dp_read_desc [drm_kms_helper]] DP sink: OUI ba-41-59 > > dev-ID HW-rev 0.0 SW-rev 0.0 quirks 0x0000 > > [ 3.143012] [drm:intel_dp_init_connector [i915]] eDP DPCD: 05 9d a6 > > > > If you need any more information just let me know and I'll be happy to > > uplaod it > > How old is the kernel? Can you attach the full dmesg with kernel parameters > drm.debug=0x1e log_buf_len=4M to see more information about the issue? I'm seeing this with drm-tip, and I just rechecked today and the issue is still present. I'm about to attach the dmesg you asked for as well
Created attachment 146027 [details] dmesg (drm.debug=0x1e log_buf_len=4M, dpcd aux backlight left disabled + no patches)
Created attachment 146028 [details] dmesg (drm.debug=0x1e log_buf_len=4M, dpcd aux backlight enabled manually + no patches)
(In reply to Lyude Paul from comment #0) > Created attachment 146015 [details] > VBIOS > > Filing this at the request of some of the Intel folks. I recently got my > hand on a ThinkPad X1 Extreme 2nd Generation with the optional 4K AMOLED > screen, and discovered that backlight controls weren't working. While there > seems to be multiple problems here, all of which I've come up with some > patches for that I plan to send out after filing this bug, one of the big > things I noticed was that despite requiring DPCD backlight control this > laptop claims to be using PWM backlight controls in it's vbios. So, I'm > filing this bug to upload the vbios along with DPCD and other relevant > information here. > > As well, here's a dump of some relevant DPCD registers: > > [ 3.142168] [drm:intel_dp_read_dpcd [i915]] DPCD: 14 14 c4 01 00 00 01 c0 > 02 14 00 00 00 08 82 > [ 3.142600] [drm:drm_dp_read_desc [drm_kms_helper]] DP sink: OUI ba-41-59 > dev-ID HW-rev 0.0 SW-rev 0.0 quirks 0x0000 > [ 3.143012] [drm:intel_dp_init_connector [i915]] eDP DPCD: 05 9d a6 > > If you need any more information just let me know and I'll be happy to > uplaod it @Jani, Any comments? Logs from drmtip is attached in the bug.
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