<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [SKL] Flashing black screen ([drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun)" href="https://bugs.freedesktop.org/show_bug.cgi?id=94605#c81">Comment # 81</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [SKL] Flashing black screen ([drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun)" href="https://bugs.freedesktop.org/show_bug.cgi?id=94605">bug 94605</a> from <a class="email" href="mailto:registo.mailling@gmail.com" title="Mauro Santos <registo.mailling@gmail.com>"> Mauro Santos</a> <pre>(In reply to Peter Wu from <a href="show_bug.cgi?id=94605#c80">comment #80</a>) > Under what circumstances? Any special cmdline, patches or userspace > packages? So far it seems to work for me (i7-6700HQ, Arch Linux, 4.8.6-1). I'm also on Arch with kernel 4.8.6-1. I have an i7-6500U. I guess the only "special" thing I have on the cmdline is intel_iommu=on, but I don't see any memory errors as reported by syphyr. I have a way to avoid the problems, but that will limit the package c-state to PC2, let me try to explain. If I do not do modifications to any of the kernel's defaults, the cpu never gets to a package c-state lower than PC2 (1)(or higher, whichever way you want to see it). If I enable sata ALPM then the cpu will to go into PC6 and that is when I start to see the problem. Further, if I turn on auto suspend for a usb bluetooth device, the cpu will now get into PC7 and I also see the problem in this case. I have not been able to get the cpu to go into PC8~PC10 even when doing all the changes recommended by powertop. (1) The cpu's datasheet states clearly that "Long term reliability cannot be assured unless all the Low-Power Idle States are enabled.". I'm not sure if this applies to package c-states but even if it doesn't I would like the cpu to be as efficient as possible so that I get more time when using battery and so that there is less heat and noise.</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 assignee for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>