<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - PSR causes graphical glitches on Dell XPS 15 9570" href="https://bugs.freedesktop.org/show_bug.cgi?id=111701#c16">Comment # 16</a> on <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - PSR causes graphical glitches on Dell XPS 15 9570" href="https://bugs.freedesktop.org/show_bug.cgi?id=111701">bug 111701</a> from <a class="email" href="mailto:sultan@kerneltoast.com" title="Sultan Alsawaf <sultan@kerneltoast.com>"> Sultan Alsawaf</a> <pre>> Compared your patch with mine, the result of both should be the same, did > you spot any difference? > I'm sure that other developers will not like this manual string comparison > too. It's not the same because your patch does not adhere to the EDID specification. According to the EDID standard (<a href="https://en.wikipedia.org/wiki/Extended_Display_Identification_Data#Display_Descriptors">https://en.wikipedia.org/wiki/Extended_Display_Identification_Data#Display_Descriptors</a>), the 13 bytes of text for the display descriptor are terminated with a line feed character when the length of the content is less than 13 bytes (it's not terminated with a zero byte, which is what your strncmp assumes). My panel model string is less than 13 bytes ("TK6R7"), but my EDID is malformed and the model string is terminated with a 0x80 character. So in my patch, I made panel_in_psr2_blacklist() interpret any !isgraph character as a terminating character, which is what the edid-decode tool does as well. Here's the raw dump of my EDID for you to see: 00000000: 00 ff ff ff ff ff ff 00 4d 10 9a 14 00 00 00 00 ........M....... 00000010: 04 1c 01 04 a5 22 13 78 0e de 50 a3 54 4c 99 26 .....".x..P.TL.& 00000020: 0f 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01 .PT............. 00000030: 01 01 01 01 01 01 ac 37 80 a0 70 38 3e 40 30 20 .......7..p8>@0 00000040: 35 00 58 c2 10 00 00 18 00 00 00 00 00 00 00 00 5.X............. 00000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 fe 00 54 ...............T 00000060: 4b 36 52 37 80 4c 51 31 35 36 4d 31 00 00 00 00 K6R7.LQ156M1.... 00000070: 00 02 41 03 28 00 12 00 00 0a 01 0a 20 20 00 2b ..A.(....... .+ > Running Ubuntu 18.10 with drm-tip kernel on a Whiskey Lake reference > platform, all GEN9 are very similar on display so I should be able to > reproduce it if I had the exactly same panel model as you. I'm running Ubuntu 19.10 with drm-tip. Try using that, and then change the login screen background to make the glitch much easier to see. To change the login screen background, run this long command: sudo perl -i -p0e 's,(#lockDialogGroup.*?)},#lockDialogGroup {\nbackground: #2c001e url(file:///usr/share/backgrounds/Staniel_Cay_by_Joseph_Bylund.jpg);\nbackground-repeat: no-repeat;\nbackground-size: cover;\nbackground-position: center;\n},s' /usr/share/gnome-shell/theme/gdm3.css Then keep rebooting until you see the glitch in my video, assuming your setup is affected.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>