On Tue, 23 Sep 2014, 陳勇秀 <greatshow.chen@xxxxxxxxx> wrote: > Hi All, > > I am using a baytrail cpu and linux kernel 3.14.7, and will echo some > message to /dev/tty1 during boot. > > There is chance that no display output during boot, but I can use linux via > ttyS4, the HSUART. > > Attached is output of intel_reg_dumper, > display.fail is register dump that no display output. > display_ok is register dump that display works. > > There is difference between: > > DPLL_A_MD: 0x60ff2cdf (ok) > DPLL_A_MD: 0x70ff2ddf (fail) > > DPLL_B: 0x60ff2cdf (disabled, dvo, VGA, TV A clock, unknown mode, p1 = 1, > p2 = 0) (ok) > DPLL_B: 0x70ff2ddf (disabled, dvo, TV A clock, unknown mode, p1 = 1, p2 = > 0, using FPx1!) (fail) > > The bios dump is also attached. How do I read the bios dump file? > > The problem can be reproduced even I update kernel to 3.14.18. > > > It's interesting the no display issue never happens if I boot into x-window > system. Please file a bug against DRM/Intel at [1], attach dmesg all the way from boot to the problem with drm.debug=14 module parameter set. BR, Jani. [1] https://bugs.freedesktop.org/enter_bug.cgi?product=DRI -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
