On Thu, 2012-04-26 at 22:07 +0200, Daniel Vetter wrote: > On Wed, Apr 25, 2012 at 10:28:41AM -0700, Kamal Mostafa wrote: > > i915.enable_backlight=0 can be used to disable i915 backlight control > > and the /sys/class/backlight/intel_backlight interface -- useful for > > systems where intel_backight conflicts with BIOS backlight control. > > > > BugLink: https://launchpad.net/bugs/954661 > > Signed-off-by: Kamal Mostafa <kamal at canonical.com> > > Ok, I've just gone through the fun of merging a set of backlight quirks a > few weeks back. Then noticed that an awful lot of machines seem to be > affected and later on read about a few interesting bits in the > documentation. Turns out the hw is all good, it's just the driver totally > mishandling the backlight. > > To cut things short: This time around I want more justification for the > quirk than just "this makes this one machine work somehow". The enable_backlight modparam (this PATCH 1/2) would be generally useful to have, whether or not we quirk-disable it for that particular machine. Consider accepting this first patch 1/2 on its own? -Kamal > > --- > > drivers/gpu/drm/i915/i915_drv.c | 6 ++++++ > > drivers/gpu/drm/i915/i915_drv.h | 1 + > > drivers/gpu/drm/i915/intel_panel.c | 12 ++++++++++++ > > 3 files changed, 19 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c > > index ae8a64f..ddb947b 100644 > > --- a/drivers/gpu/drm/i915/i915_drv.c > > +++ b/drivers/gpu/drm/i915/i915_drv.c > > @@ -112,6 +112,12 @@ module_param_named(i915_enable_ppgtt, i915_enable_ppgtt, int, 0600); > > MODULE_PARM_DESC(i915_enable_ppgtt, > > "Enable PPGTT (default: true)"); > > > > +int i915_enable_backlight __read_mostly = -1; > > +module_param_named(enable_backlight, i915_enable_backlight, int, 0644); > > +MODULE_PARM_DESC(enable_backlight, > > + "Enable backlight control and the intel_backlight interface. " > > + "(default: -1 (auto))"); > > + > > static struct drm_driver driver; > > extern int intel_agp_enabled; > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > > index 5fabc6c..6e52a42 100644 > > --- a/drivers/gpu/drm/i915/i915_drv.h > > +++ b/drivers/gpu/drm/i915/i915_drv.h > > @@ -1087,6 +1087,7 @@ extern int i915_enable_rc6 __read_mostly; > > extern int i915_enable_fbc __read_mostly; > > extern bool i915_enable_hangcheck __read_mostly; > > extern int i915_enable_ppgtt __read_mostly; > > +extern int i915_enable_backlight __read_mostly; > > > > extern int i915_suspend(struct drm_device *dev, pm_message_t state); > > extern int i915_resume(struct drm_device *dev); > > diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c > > index 48177ec..fcecbd2 100644 > > --- a/drivers/gpu/drm/i915/intel_panel.c > > +++ b/drivers/gpu/drm/i915/intel_panel.c > > @@ -259,6 +259,9 @@ void intel_panel_disable_backlight(struct drm_device *dev) > > { > > struct drm_i915_private *dev_priv = dev->dev_private; > > > > + if (!i915_enable_backlight) > > + return; > > + > > dev_priv->backlight_enabled = false; > > intel_panel_actually_set_backlight(dev, 0); > > } > > @@ -267,6 +270,9 @@ void intel_panel_enable_backlight(struct drm_device *dev) > > { > > struct drm_i915_private *dev_priv = dev->dev_private; > > > > + if (!i915_enable_backlight) > > + return; > > + > > if (dev_priv->backlight_level == 0) > > dev_priv->backlight_level = intel_panel_get_max_backlight(dev); > > > > @@ -333,6 +339,9 @@ int intel_panel_setup_backlight(struct drm_device *dev) > > struct backlight_properties props; > > struct drm_connector *connector; > > > > + if (!i915_enable_backlight) > > + return 0; > > + > > intel_panel_init_backlight(dev); > > > > if (dev_priv->int_lvds_connector) > > @@ -368,6 +377,9 @@ void intel_panel_destroy_backlight(struct drm_device *dev) > > #else > > int intel_panel_setup_backlight(struct drm_device *dev) > > { > > + if (!i915_enable_backlight) > > + return; > > + > > intel_panel_init_backlight(dev); > > return 0; > > } > > -- > > 1.7.5.4 > > > > _______________________________________________ > > Intel-gfx mailing list > > Intel-gfx at lists.freedesktop.org > > http://lists.freedesktop.org/mailman/listinfo/intel-gfx >
