[Intel-gfx] [PATCH] drm/i915: bdw does not have pch backlight override bit

[Jani Nikula]

On Thu, 04 Sep 2014, Ville Syrjälä <ville.syrjala at linux.intel.com> wrote:
> On Thu, Sep 04, 2014 at 02:56:09PM +0300, Jani Nikula wrote:
>> BDW is always in the PCH override mode, and the bit MBZ.
>
> BSpec doesn't seem to agree. In fact it says the override must be
> enabled on bdw.

Gah, I was looking at the skl bspec, which said bdw+. Oh well, how about
this one instead:


>From 53db5d77cf8e959ed65535f2d80f721baf74d93a Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula at intel.com>
Date: Thu, 4 Sep 2014 14:54:34 +0300
Subject: [PATCH] drm/i915: skl does not have pch backlight override bit
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Cc: Jani Nikula <jani.nikula at intel.com>

SKL is always in the PCH override mode, and the bit MBZ.

Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/i915/intel_panel.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 18784470a760..bc3e74eaf52e 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -781,7 +781,8 @@ static void bdw_enable_backlight(struct intel_connector *connector)
 		pch_ctl1 |= BLM_PCH_POLARITY;
 
 	/* BDW always uses the pch pwm controls. */
-	pch_ctl1 |= BLM_PCH_OVERRIDE_ENABLE;
+	if (IS_BROADWELL(dev))
+		pch_ctl1 |= BLM_PCH_OVERRIDE_ENABLE;
 
 	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
 	POSTING_READ(BLC_PWM_PCH_CTL1);
-- 
1.9.1




>
>> 
>> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> ---
>>  drivers/gpu/drm/i915/intel_panel.c | 3 ---
>>  1 file changed, 3 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
>> index 18784470a760..066a66165cf1 100644
>> --- a/drivers/gpu/drm/i915/intel_panel.c
>> +++ b/drivers/gpu/drm/i915/intel_panel.c
>> @@ -780,9 +780,6 @@ static void bdw_enable_backlight(struct intel_connector *connector)
>>  	if (panel->backlight.active_low_pwm)
>>  		pch_ctl1 |= BLM_PCH_POLARITY;
>>  
>> -	/* BDW always uses the pch pwm controls. */
>> -	pch_ctl1 |= BLM_PCH_OVERRIDE_ENABLE;
>> -
>>  	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
>>  	POSTING_READ(BLC_PWM_PCH_CTL1);
>>  	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_PWM_ENABLE);
>> -- 
>> 1.9.1
>> 
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> -- 
> Ville Syrjälä
> Intel OTC

-- 
Jani Nikula, Intel Open Source Technology Center