On Mon, Apr 23, 2012 at 01:54:23PM +0200, Carsten Emde wrote: > On 04/23/2012 11:32 AM, Daniel Vetter wrote: > >There's a bit in the docs for gen4 only that says whether the > >backlight control is inverted. And both the quirk we have and > >all bugs only concern i965gm and gm45 (and mostly Acer) afaics. > > > >So lets drop the quirk and use the bit instead. > > > >Also clean up the BLC register definitions a bit by correctly > >grouping the CTL and CTL2 definitions together. > >[..] > >diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > >index 4c844c6..5d215f0 100644 > >--- a/drivers/gpu/drm/i915/intel_display.c > >+++ b/drivers/gpu/drm/i915/intel_display.c > >@@ -6482,9 +6482,6 @@ static struct intel_quirk intel_quirks[] = { > > > > /* Sony Vaio Y cannot use SSC on LVDS */ > > { 0x0046, 0x104d, 0x9076, quirk_ssc_force_disable }, > >- > >- /* Acer Aspire 5734Z must invert backlight brightness */ > >- { 0x2a42, 0x1025, 0x0459, quirk_invert_brightness }, > Made a first test with these lines removed and the new mechanism > added. Unfortunately, the screen is now dark again. Works after > re-adding the quirk. > > >+ /* gen4 has a polarity bit */ > >+ if (IS_GEN4(dev) && (I915_READ(BLC_PWM_CTL2) & BLM_POLARITY_I965)) > >+ return intel_panel_get_max_backlight(dev) - val; > >+ > Apparently, these conditions are not met on the Acer Aspire 5734Z. > Will add some debug output and evaluate further. For the time being, > please leave the quirk in place. Hm, I've tried this and when I set this bit, panel brightness is inverted on my gm45. Can you install intel-gpu-tools and read out the 2 backlight control registers with # intel_reg_read 0x61254 # intel_reg_read 0x61250 Thanks, Daniel -- Daniel Vetter Mail: daniel at ffwll.ch Mobile: +41 (0)79 365 57 48