So let's use it. We already correctly ignore bit0 on gen < 4, now we also now why ;-) I've decided that losing that single bit of precision isn't worth the trouble to sprinkle IS_PINEVIEW checks all over the backlight control code - that code is way too fragile imo. Cc: Chris Wilson <chris at chris-wilson.co.uk> Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch> --- drivers/gpu/drm/i915/i915_reg.h | 2 ++ drivers/gpu/drm/i915/intel_panel.c | 5 +++-- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 67c4ca0..45d5568 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -1805,6 +1805,8 @@ */ #define BACKLIGHT_DUTY_CYCLE_SHIFT (0) #define BACKLIGHT_DUTY_CYCLE_MASK (0xffff) +#define BACKLIGHT_DUTY_CYCLE_MASK_PNV (0xfffe) +#define BLM_POLARITY_PNV (1 << 0) /* pnv only */ #define BLC_HIST_CTL 0x61260 diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index 1874517..e519221 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -212,8 +212,9 @@ static u32 intel_panel_compute_brightness(struct drm_device *dev, u32 val) dev_priv->quirks & QUIRK_INVERT_BRIGHTNESS) return intel_panel_get_max_backlight(dev) - val; - /* gen4 has a polarity bit */ - if (IS_GEN4(dev) && (I915_READ(BLC_PWM_CTL2) & BLM_POLARITY_I965)) + /* gen4/pnv has a polarity bit */ + if (IS_GEN4(dev) && (I915_READ(BLC_PWM_CTL2) & BLM_POLARITY_I965) || + IS_PINEVIEW(dev) && (I915_READ(BLC_PWM_CTL) & BLM_POLARITY_PNV)) return intel_panel_get_max_backlight(dev) - val; return val; -- 1.7.10
