Laptop Packard Bell EasyNote TK37, kernel 3.10.14, Slackware64-current. When booting using kernel mode setting, screen goes black after a few seconds. lspci -vnn reports: 00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a42] (rev 07) (prog-if 00 [VGA controller]) Subsystem: Acer Incorporated [ALI] Device [1025:048a] Flags: bus master, fast devsel, latency 0, IRQ 44 Memory at d0000000 (64-bit, non-prefetchable) [size=4M] Memory at c0000000 (64-bit, prefetchable) [size=256M] s at 5110 [size=8] Expansion ROM at <unassigned> [disabled] Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- Capabilities: [d0] Power Management version 3 Kernel driver in use: i915 appending i915.invert_brightness=1 to the command lines works this is a common problem with this chipset, so I suggest patching file: drivers/gpu/drm/i915/intel_display.c like this: /* Acer Aspire 4736Z */ { 0x2a42, 0x1025, 0x0260, quirk_invert_brightness }, + /* Packard Bell EasyNote TK37 */ + { 0x2a42, 0x1025, 0x048a, quirk_invert_brightness }, Rebuilding the kernel after that works. Cheers, Didier
We've decided to quirk them all, it's easier ;-) commit ee1452d7458451a7508e0663553ce88d63958157 Author: Jani Nikula <jani.nikula@intel.com> Date: Fri Sep 20 15:05:30 2013 +0300 drm/i915: assume all GM45 Acer laptops use inverted backlight PWM
Note that I've decided to play it safe and merged the patch only for linux-next / v3.13, in case there's a packard bell/acer out there which doesn't need this. We can backport this later, meanwhile you can either keep your quirk entry or cherry-pick the commit from linux-next.