<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Arial; font-size: 12pt; color: #000000'> <hr id="zwchr">From: "Jonathan Nieder" <jrnieder@gmail.com> To: "Keith Packard" <keithp@keithp.com> Cc: "Joel Heaton" <jheaton5@comcast.net>, intel-gfx@lists.freedesktop.org Sent: Wednesday, February 22, 2012 6:03:08 AM Subject: Re: Screen goes blank @30 seconds into boot (resending after subscription to appease list spam filter. Keith and Joel, sorry for the duplicate message) Hi intel-gfx list, Keith Packard wrote: > On Thu, 26 Jan 2012 06:54:48 -0500, Joel Heaton <jheaton5@comcast.net> wrote: >> System: Dell Inspiron One >> Chipset: intel H61 Express >> CPU: Intel Pentium Dual Core Intel Core i3/i5i7 (this machine is >> probably an i3 >> Video: Intel HD/HD 2000/HD 3000 [...] >> When booting the screen goes blank about 80% through the boot cycle. >> The system is still running, I can log in blind and execute reboot >> command. > > Is the monitor backlight on or off? If off, can you try finding a bright > light and shining it on the monitor to see if the image is present, but > the backlight simply disabled? Interesting question. Joel? Sorry about not answering this question. I do not see the image on the screen with a bright light. >> I ssh into the system from another computer. >> kern.log reports "Firmware Bug: ACPI: No _BQC method, cannot determine >> initial brightness" > > The last bug we saw with this was a system that did leave the monitor > off. Here's a patch that fixed that machine: > > Keith Packard <keithp@keithp.com> (December 31) (lkml me patch sent) > Subject: [PATCH] acpi/video: Don't restore backlight to 0 at boot time No change, alas, when Joel tried this patch[1]: | I made the change by editing drivers/acpi/video.c but the bug is | recreated. Cherry-picking commit 7885d2052bd ("drm/i915: mask transcoder select bits before setting them on LVDS") did not help either. More details including some kernel logs and an acpidump at [1]. Thanks and hope that helps, Jonathan [1] http://bugs.debian.org/660394 </div></body></html>