On Fri, Jul 19, 2013 at 03:02:01PM -0700, Kamal Mostafa wrote: > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=47941 > BugLink: https://bugs.launchpad.net/bugs/1163720 > BugLink: https://bugs.launchpad.net/bugs/1162026 > > Some machines suffer from non-functional backlight controls if > BLM_PCH_PWM_ENABLE is set, so provide a quirk to avoid doing so. > Apply this quirk to Dell XPS 13 models. > > Tested-by: Eric Griffith <EGriffith92@xxxxxxxxx> > Tested-by: Kent Baxley <kent.baxley@xxxxxxxxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> # v3.8+ > Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx> I still wonder what exactly's going on here, but for backlight stuff I've given up on avoiding quirks ;-) Thanks for digging into this, patch applied to -fixes. -Daniel > --- > drivers/gpu/drm/i915/i915_drv.h | 1 + > drivers/gpu/drm/i915/intel_display.c | 16 ++++++++++++++++ > drivers/gpu/drm/i915/intel_panel.c | 3 ++- > 3 files changed, 19 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index a416645..204c3ec 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -555,6 +555,7 @@ enum intel_sbi_destination { > #define QUIRK_PIPEA_FORCE (1<<0) > #define QUIRK_LVDS_SSC_DISABLE (1<<1) > #define QUIRK_INVERT_BRIGHTNESS (1<<2) > +#define QUIRK_NO_PCH_PWM_ENABLE (1<<3) > > struct intel_fbdev; > struct intel_fbc_work; > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index 85f3eb7..42e207e 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -9398,6 +9398,17 @@ static void quirk_invert_brightness(struct drm_device *dev) > DRM_INFO("applying inverted panel brightness quirk\n"); > } > > +/* > + * Some machines (Dell XPS13) suffer broken backlight controls if > + * BLM_PCH_PWM_ENABLE is set. > + */ > +static void quirk_no_pcm_pwm_enable(struct drm_device *dev) > +{ > + struct drm_i915_private *dev_priv = dev->dev_private; > + dev_priv->quirks |= QUIRK_NO_PCH_PWM_ENABLE; > + DRM_INFO("applying no-PCH_PWM_ENABLE quirk\n"); > +} > + > struct intel_quirk { > int device; > int subsystem_vendor; > @@ -9467,6 +9478,11 @@ static struct intel_quirk intel_quirks[] = { > > /* Acer Aspire 4736Z */ > { 0x2a42, 0x1025, 0x0260, quirk_invert_brightness }, > + > + /* Dell XPS13 HD Sandy Bridge */ > + { 0x0116, 0x1028, 0x052e, quirk_no_pcm_pwm_enable }, > + /* Dell XPS13 HD and XPS13 FHD Ivy Bridge */ > + { 0x0166, 0x1028, 0x058b, quirk_no_pcm_pwm_enable }, > }; > > static void intel_init_quirks(struct drm_device *dev) > diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c > index 80bea1d..01b5a51 100644 > --- a/drivers/gpu/drm/i915/intel_panel.c > +++ b/drivers/gpu/drm/i915/intel_panel.c > @@ -580,7 +580,8 @@ void intel_panel_enable_backlight(struct drm_device *dev, > POSTING_READ(reg); > I915_WRITE(reg, tmp | BLM_PWM_ENABLE); > > - if (HAS_PCH_SPLIT(dev)) { > + if (HAS_PCH_SPLIT(dev) && > + !(dev_priv->quirks & QUIRK_NO_PCH_PWM_ENABLE)) { > tmp = I915_READ(BLC_PWM_PCH_CTL1); > tmp |= BLM_PCH_PWM_ENABLE; > tmp &= ~BLM_PCH_OVERRIDE_ENABLE; > -- > 1.8.1.2 > -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
