[Bug 112376] New: ThinkPad X1 Extreme 2nd Generation does not advertise DPCD backlight in vbios

bugzilla-daemon at freedesktop.org bugzilla-daemon at freedesktop.org
Fri Nov 22 21:18:05 UTC 2019


https://bugs.freedesktop.org/show_bug.cgi?id=112376

            Bug ID: 112376
           Summary: ThinkPad X1 Extreme 2nd Generation does not advertise
                    DPCD backlight in vbios
           Product: DRI
           Version: DRI git
          Hardware: Other
                OS: All
            Status: NEW
          Severity: not set
          Priority: not set
         Component: DRM/Intel
          Assignee: intel-gfx-bugs at lists.freedesktop.org
          Reporter: lyude at redhat.com
        QA Contact: intel-gfx-bugs at lists.freedesktop.org
                CC: intel-gfx-bugs at lists.freedesktop.org

Created attachment 146015
  --> https://bugs.freedesktop.org/attachment.cgi?id=146015&action=edit
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

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are on the CC list for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20191122/f2300b3a/attachment.html>


More information about the intel-gfx-bugs mailing list