BLM_PCH_POLARITY
panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
pch_ctl1 |= BLM_PCH_POLARITY;
pch_ctl1 |= BLM_PCH_POLARITY;