On Fri, 22 Nov 2019, Lyude Paul <lyude@xxxxxxxxxx> wrote: > Turns out we actually already have some companies, such as Lenovo, > shipping machines with AMOLED screens that don't allow controlling the > backlight through the usual PWM interface and only allow controlling it > through the standard EDP DPCD interface. One example of one of these > laptops is the X1 Extreme 2nd Generation. > > Since we've got systems that need this turned on by default now to have > backlight controls working out of the box, let's start auto-detecting it > for systems by default based on what the VBT tells us. We do this by > changing the default value for the enable_dpcd_backlight module param > from 0 to -1. > > Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx> Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx> > --- > drivers/gpu/drm/i915/i915_params.c | 2 +- > drivers/gpu/drm/i915/i915_params.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c > index 1dd1f3652795..31eed60c167e 100644 > --- a/drivers/gpu/drm/i915/i915_params.c > +++ b/drivers/gpu/drm/i915/i915_params.c > @@ -172,7 +172,7 @@ i915_param_named_unsafe(inject_probe_failure, uint, 0400, > > i915_param_named(enable_dpcd_backlight, int, 0600, > "Enable support for DPCD backlight control" > - "(-1=use per-VBT LFP backlight type setting, 0=disabled [default], 1=enabled)"); > + "(-1=use per-VBT LFP backlight type setting [default], 0=disabled, 1=enabled)"); > > #if IS_ENABLED(CONFIG_DRM_I915_GVT) > i915_param_named(enable_gvt, bool, 0400, > diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h > index 31b88f297fbc..a79d0867f77a 100644 > --- a/drivers/gpu/drm/i915/i915_params.h > +++ b/drivers/gpu/drm/i915/i915_params.h > @@ -64,7 +64,7 @@ struct drm_printer; > param(int, reset, 3) \ > param(unsigned int, inject_probe_failure, 0) \ > param(int, fastboot, -1) \ > - param(int, enable_dpcd_backlight, 0) \ > + param(int, enable_dpcd_backlight, -1) \ > param(char *, force_probe, CONFIG_DRM_I915_FORCE_PROBE) \ > param(unsigned long, fake_lmem_start, 0) \ > /* leave bools at the end to not create holes */ \ -- Jani Nikula, Intel Open Source Graphics Center _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
