<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - ThinkPad X1 Extreme 2nd Generation does not advertise DPCD backlight in vbios" href="https://bugs.freedesktop.org/show_bug.cgi?id=112376#c2">Comment # 2</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - ThinkPad X1 Extreme 2nd Generation does not advertise DPCD backlight in vbios" href="https://bugs.freedesktop.org/show_bug.cgi?id=112376">bug 112376</a> from <a class="email" href="mailto:lyude@redhat.com" title="Lyude Paul <lyude@redhat.com>"> Lyude Paul</a> <pre>(In reply to Lakshmi from <a href="show_bug.cgi?id=112376#c1">comment #1</a>) > (In reply to Lyude Paul from <a href="show_bug.cgi?id=112376#c0">comment #0</a>) > > Created <a href="attachment.cgi?id=146015" name="attach_146015" title="VBIOS">attachment 146015</a> <a href="attachment.cgi?id=146015&action=edit" title="VBIOS">[details]</a> > > 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</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are on the CC list for the bug.</li> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>