On Thu, 15 Mar 2012 10:52:21 +0100, Carsten Emde <C.Emde@xxxxxxxxx> wrote: > Following the documentation of the Legacy Backlight Brightness (LBB) > Register in the configuration space of some Intel PCI graphics adapters, > setting the LBB register with the value 0x0 causes the backlight to be > turned off, and 0xFF causes the backlight to be set to 100% intensity > (http://download.intel.com/embedded/processors/Whitepaper/324567.pdf). > The Acer Aspire 5734Z, however, turns the backlight off at 0xFF and sets > it to maximum intensity at 0. In consequence, the screen of this systems > becomes dark at an early boot stage which makes it unusable. The same > inversion applies to the BLC_PWM_CTL I915 register. This problem was > introduced in kernel version 2.6.38 when the PCI device of this system > was first supported by the i915 KMS module. > > This patch adds a quirk to invert the sense of the brightness variable > in case an Acer Aspire 5734Z is encountered. > > Signed-off-by: Carsten Emde <C.Emde@xxxxxxxxx> That looks a lot better. However, can I ask for another follow-on patch to enable this quirk by a module parameter as well? I would like to make it easier for anyone else hitting this issue to identity the problem and find a temporary solution until their machine is also quirked. > static void intel_init_quirks(struct drm_device *dev) > Index: linux-3.3-rc7/drivers/gpu/drm/i915/intel_panel.c > =================================================================== > --- linux-3.3-rc7.orig/drivers/gpu/drm/i915/intel_panel.c > +++ linux-3.3-rc7/drivers/gpu/drm/i915/intel_panel.c > @@ -28,6 +28,7 @@ > * Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > */ > > +#include <linux/moduleparam.h> > #include "intel_drv.h" That include is now not required. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
