<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - Flickering Screen on Dell XPS13 9350" href="https://bugs.freedesktop.org/show_bug.cgi?id=94593#c44">Comment # 44</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - Flickering Screen on Dell XPS13 9350" href="https://bugs.freedesktop.org/show_bug.cgi?id=94593">bug 94593</a> from <a class="email" href="mailto:peteryuchuang@gmail.com" title="Peter Y. Chuang <peteryuchuang@gmail.com>"> Peter Y. Chuang</a> <pre>(In reply to nhellwege from <a href="show_bug.cgi?id=94593#c43">comment #43</a>) > (In reply to tranceash from <a href="show_bug.cgi?id=94593#c38">comment #38</a>) > > looks like a power management issues dating 8 months back, Also happened on > > the broadwell systems <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [bdw edp] Screen Flickering" href="show_bug.cgi?id=91393">https://bugs.freedesktop.org/show_bug.cgi?id=91393</a>. > > This makes any linux system a pain to work because of this integrated gpu > > driver . Skylake has been out for 7 months and we still have problems > > I am starting to believe that the common error > > [drm:intel_cpu_fifo_underrun_irq_handler [i915_bpo]] *ERROR* CPU pipe A > FIFO underrun > > is not actually responsible for the flicker. To be more precise, the FIFO > underrun may result in conjunction with a flicker, but is not a unique > indication. I am currently bisecting the kernel and right now I am on commit > 5ffd4da+. This commit does show the FIFO underun but not at the same time > the screen turns completely black for a split second. > > I assume the flicker (screen completely black for a split second) is not > directly mapped by the FIFO underrun. > > Reading <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [bdw edp] Screen Flickering" href="show_bug.cgi?id=91393">https://bugs.freedesktop.org/show_bug.cgi?id=91393</a>, I think our bug > is at least related, if not identical. I tend to agree with you that the error [drm:intel_cpu_fifo_underrun_irq_handler [i915_bpo]] *ERROR* CPU pipe A FIFO underrun may not be specific to the problem we are talking about here. Regarding my previous comment on whether the laptop is plugged into AC, Thomas is right: if I wait long enough, the flicker does occur even when plugged in, although much less frequent on my machine. Interestingly, now that I am plugged into AC, the CPU pipe A FIFO underrun thing is no longer the error I see. Instead, this is the error I saw on dmesg: [ 2045.481992] [drm:intel_pipe_update_end [i915]] *ERROR* Atomic update failure on pipe A (start=84070 end=84071) time 9 us, min 1073, max 1079, scanline start 1087, end 1079 This is the first time I see this error since I started looking for the solution for this problem. Hope this might give you some clues.</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> </ul> </body> </html>