[Intel-gfx] [RESEND FOR CI PATCH v2] drm/i915: Fix eDP low vswing for Broadwell

[Jani Nikula]

On Wed, 20 Apr 2016, Mika Kahola <mika.kahola at intel.com> wrote:
> CI hasn't catch this patch for testing?

It has http://mid.gmane.org/20160413170704.11600.78300@emeril.freedesktop.org

>
> On Wed, 2016-04-13 at 12:11 +0300, Mika Kahola wrote:
>> It was noticed on bug #94087 that module parameter
>> i915.edp_vswing=2 that should override the VBT setting
>> to use default voltage swing (400 mV) was not applied
>> for Broadwell.
>> 
>> This patch provides a fix for this by checking if default
>> i.e. higher voltage swing is requested to be used and
>> applies the DDI translations table for DP instead of eDP
>> (low vswing) table.
>> 
>> v2: Combine two if statements into one (Jani)
>> 
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94087
>> Signed-off-by: Mika Kahola <mika.kahola at intel.com>
>> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> ---
>>  drivers/gpu/drm/i915/intel_ddi.c | 12 ++++++++++--
>>  1 file changed, 10 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
>> index 921edf1..d9af2de 100644
>> --- a/drivers/gpu/drm/i915/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/intel_ddi.c
>> @@ -443,9 +443,17 @@ void intel_prepare_ddi_buffer(struct intel_encoder *encoder)
>>  	} else if (IS_BROADWELL(dev_priv)) {
>>  		ddi_translations_fdi = bdw_ddi_translations_fdi;
>>  		ddi_translations_dp = bdw_ddi_translations_dp;
>> -		ddi_translations_edp = bdw_ddi_translations_edp;
>> +
>> +		if (dev_priv->edp_low_vswing) {
>> +			ddi_translations_edp = bdw_ddi_translations_edp;
>> +			n_edp_entries = ARRAY_SIZE(bdw_ddi_translations_edp);
>> +		} else {
>> +			ddi_translations_edp = bdw_ddi_translations_dp;
>> +			n_edp_entries = ARRAY_SIZE(bdw_ddi_translations_dp);
>> +		}
>> +
>>  		ddi_translations_hdmi = bdw_ddi_translations_hdmi;
>> -		n_edp_entries = ARRAY_SIZE(bdw_ddi_translations_edp);
>> +
>>  		n_dp_entries = ARRAY_SIZE(bdw_ddi_translations_dp);
>>  		n_hdmi_entries = ARRAY_SIZE(bdw_ddi_translations_hdmi);
>>  		hdmi_default_entry = 7;

-- 
Jani Nikula, Intel Open Source Technology Center