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<b><a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - LVDS blank screen on GM45"
href="https://bugs.freedesktop.org/show_bug.cgi?id=94825#c13">Comment # 13</a>
on <a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - LVDS blank screen on GM45"
href="https://bugs.freedesktop.org/show_bug.cgi?id=94825">bug 94825</a>
from <span class="vcard"><a class="email" href="mailto:rob@solution-space.com" title="Rob Kramer <rob@solution-space.com>"> <span class="fn">Rob Kramer</span></a>
</span></b>
<pre>Some things I could try:
1) Override broken panel type via module parameter.
2) Disable VBT via module parameter, force use of existing mode.
3) Use video=.. parameter to lookup matching VBT panel.
I've tried option 1, hack panel_type to 15 in intel_bios.c, and that works:
[ 4.770027] [drm:intel_lvds_init] using mode from VBT:
[ 4.770030] [drm:drm_mode_debug_printmodeline] Modeline 0:"1920x1080" 0
148500 1920 2040 2080 2200 1080 1081 1092 1125 0x8 0xa
[ 4.770033] [drm:intel_lvds_init] detected dual-link lvds configuration
Option 2 also works (hack out VBT setting), but results in messy kernel
warnings/backtraces about pipe state mismatches, see previously attached logs.
I don't know if option 3 is too horrible to consider.
I've applied your patch to 4.5 (with minor port), but it returns too early at:
ret = acpi_video_get_edid(acpidev, ACPI_VIDEO_DISPLAY_LCD, -1, &edid);
if (ret < 0)
return ret;
Could my kernel be missing some ACPI stuff? There is CONFIG_ACPI_VIDEO=m, and
the module is loaded. I didn't add a new boot log since there wasn't anything
new. If you have some ideas on how to debug this, please let me know (I know
very little about ACPI)..</pre>
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