Re: [PATCH v3] drm/i915: Enable pixel replicated modes on BDW and HSW.

[Clint Taylor <clinton.a.taylor@intel.com>]

On 09/26/2014 09:38 AM, Ville Syrjälä wrote:
> On Thu, Sep 25, 2014 at 10:03:53AM -0700, clinton.a.taylor@intel.com wrote:
>> From: Clint Taylor <clinton.a.taylor@intel.com>
>>
>> Haswell and later silicon has added a new pixel replication register
>> to the pipe timings for each transcoder. Now in addition to the
>> DPLL_A_MD register for the pixel clock double, we also need to write
>> to the TRANS_MULT_n (0x6002c) register to double the pixel data. Writing
>> to the DPLL only double the pixel clock.
>>
>> ver2: Macro name change from MULTIPLY to PIPE_MULTI. (Daniel)
>> ver3: Do not set pixel multiplier if transcoder is eDP (Ville)
>>
>> Cc: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= <ville.syrjala@linux.intel.com>
>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
>> Cc: Jani Nikula <jani.nikula@intel.com>
>>
>> Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_reg.h      |    3 +++
>>   drivers/gpu/drm/i915/intel_display.c |   10 +++++++++-
>>   2 files changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index ad8179b..035d58c 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -2443,6 +2443,7 @@ enum punit_power_well {
>>   #define _PIPEASRC	0x6001c
>>   #define _BCLRPAT_A	0x60020
>>   #define _VSYNCSHIFT_A	0x60028
>> +#define _MULTIPLY_A	0x6002c
>>
>>   /* Pipe B timing regs */
>>   #define _HTOTAL_B	0x61000
>> @@ -2454,6 +2455,7 @@ enum punit_power_well {
>>   #define _PIPEBSRC	0x6101c
>>   #define _BCLRPAT_B	0x61020
>>   #define _VSYNCSHIFT_B	0x61028
>> +#define _MULTIPLY_B	0x6102c
>>
>>   #define TRANSCODER_A_OFFSET 0x60000
>>   #define TRANSCODER_B_OFFSET 0x61000
>> @@ -2474,6 +2476,7 @@ enum punit_power_well {
>>   #define BCLRPAT(trans) _TRANSCODER2(trans, _BCLRPAT_A)
>>   #define VSYNCSHIFT(trans) _TRANSCODER2(trans, _VSYNCSHIFT_A)
>>   #define PIPESRC(trans) _TRANSCODER2(trans, _PIPEASRC)
>> +#define PIPE_MULTI(trans) _TRANSCODER2(trans, _MULTIPLY_A)
>>
>>   /* HSW+ eDP PSR registers */
>>   #define EDP_PSR_BASE(dev)                       (IS_HASWELL(dev) ? 0x64800 : 0x6f800)
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index 858011d..f8c1f11 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -4168,6 +4168,11 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
>>
>>   	intel_set_pipe_timings(intel_crtc);
>>
>> +	if (intel_crtc->config.cpu_transcoder != TRANSCODER_EDP) {
>> +		I915_WRITE(PIPE_MULTI(intel_crtc->config.cpu_transcoder),
>> +				intel_crtc->config.pixel_multiplier - 1);
>> +	}
>
> So did you verify that the register really is a transcoder register?
> Eg. set PIPE_MULT(A) to >1x and use pipe A to drive the EDP transcoder.

I did not verify. This change was done based on the fact that the 
register does not exist in the VPG HTML version of the BPEC for 
Transcoder_EDP, only TRANS_MULT_A, _B, and _C are defined.

Do we have an SI contact that can confirm?

-Clint


>
>> +
>>   	if (intel_crtc->config.has_pch_encoder) {
>>   		intel_cpu_transcoder_set_m_n(intel_crtc,
>>   				     &intel_crtc->config.fdi_m_n, NULL);
>> @@ -7853,7 +7858,10 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
>>   		pipe_config->ips_enabled = hsw_crtc_supports_ips(crtc) &&
>>   			(I915_READ(IPS_CTL) & IPS_ENABLE);
>>
>> -	pipe_config->pixel_multiplier = 1;
>> +	if (pipe_config->cpu_transcoder != TRANSCODER_EDP) {
>> +		pipe_config->pixel_multiplier =
>> +			I915_READ(PIPE_MULTI(pipe_config->cpu_transcoder)) + 1;
>> +	}
>>
>>   	return true;
>>   }
>> --
>> 1.7.9.5
>