Re: [PATCHv3 2/2] i915/display/dp: SDP CRC16 for 128b132b link layer

2023-02-14 Thread Jani Nikula
On Tue, 14 Feb 2023, Jani Nikula  wrote:
> On Tue, 07 Feb 2023, Arun R Murthy  wrote:
>> Enable SDP error detection configuration, this will set CRC16 in
>> 128b/132b link layer.
>> For Display version 13 a hardware bit31 in register VIDEO_DIP_CTL is
>> added to enable/disable SDP CRC applicable for DP2.0 only, but the
>> default value of this bit will enable CRC16 in 128b/132b hence
>> skipping this write.
>> Corrective actions on SDP corruption is yet to be defined.
>>
>> v2: Moved the CRC enable to link training init(Jani N)
>> v3: Moved crc enable to ddi pre enable 
>
> It's still in intel_dp_start_link_train()...?

Also, please post new versions as new threads instead of in-reply-to. I
don't think patchwork/CI picked this up at all, for example.

BR,
Jani

>
> BR,
> Jani.
>
>
>>
>> Signed-off-by: Arun R Murthy 
>> ---
>>  .../gpu/drm/i915/display/intel_dp_link_training.c| 12 
>>  1 file changed, 12 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c 
>> b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
>> index 3d3efcf02011..7064e465423b 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
>> @@ -1453,4 +1453,16 @@ void intel_dp_start_link_train(struct intel_dp 
>> *intel_dp,
>>  
>>  if (!passed)
>>  intel_dp_schedule_fallback_link_training(intel_dp, crtc_state);
>> +
>> +/* DP v2.0 SCR on SDP CRC16 for 128b/132b Link Layer */
>> +if (intel_dp_is_uhbr(crtc_state) && passed)
>> +drm_dp_dpcd_writeb(_dp->aux,
>> +   DP_SDP_ERROR_DETECTION_CONFIGURATION,
>> +   DP_SDP_CRC16_128B132B_EN);
>> +/*
>> + * VIDEO_DIP_CTL register bit 31 should be set to '0' to not
>> + * disable SDP CRC. This is applicable for Display version 13.
>> + * Default value of bit 31 is '0' hence discarding the write
>> + */
>> +/* TODO: Corrective actions on SDP corruption yet to be defined 
>> */
>>  }

-- 
Jani Nikula, Intel Open Source Graphics Center


Re: [PATCHv3 2/2] i915/display/dp: SDP CRC16 for 128b132b link layer

2023-02-14 Thread Jani Nikula
On Tue, 07 Feb 2023, Arun R Murthy  wrote:
> Enable SDP error detection configuration, this will set CRC16 in
> 128b/132b link layer.
> For Display version 13 a hardware bit31 in register VIDEO_DIP_CTL is
> added to enable/disable SDP CRC applicable for DP2.0 only, but the
> default value of this bit will enable CRC16 in 128b/132b hence
> skipping this write.
> Corrective actions on SDP corruption is yet to be defined.
>
> v2: Moved the CRC enable to link training init(Jani N)
> v3: Moved crc enable to ddi pre enable 

It's still in intel_dp_start_link_train()...?

BR,
Jani.


>
> Signed-off-by: Arun R Murthy 
> ---
>  .../gpu/drm/i915/display/intel_dp_link_training.c| 12 
>  1 file changed, 12 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c 
> b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> index 3d3efcf02011..7064e465423b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> @@ -1453,4 +1453,16 @@ void intel_dp_start_link_train(struct intel_dp 
> *intel_dp,
>  
>   if (!passed)
>   intel_dp_schedule_fallback_link_training(intel_dp, crtc_state);
> +
> + /* DP v2.0 SCR on SDP CRC16 for 128b/132b Link Layer */
> + if (intel_dp_is_uhbr(crtc_state) && passed)
> + drm_dp_dpcd_writeb(_dp->aux,
> +DP_SDP_ERROR_DETECTION_CONFIGURATION,
> +DP_SDP_CRC16_128B132B_EN);
> + /*
> +  * VIDEO_DIP_CTL register bit 31 should be set to '0' to not
> +  * disable SDP CRC. This is applicable for Display version 13.
> +  * Default value of bit 31 is '0' hence discarding the write
> +  */
> + /* TODO: Corrective actions on SDP corruption yet to be defined 
> */
>  }

-- 
Jani Nikula, Intel Open Source Graphics Center


[PATCHv3 2/2] i915/display/dp: SDP CRC16 for 128b132b link layer

2023-02-06 Thread Arun R Murthy
Enable SDP error detection configuration, this will set CRC16 in
128b/132b link layer.
For Display version 13 a hardware bit31 in register VIDEO_DIP_CTL is
added to enable/disable SDP CRC applicable for DP2.0 only, but the
default value of this bit will enable CRC16 in 128b/132b hence
skipping this write.
Corrective actions on SDP corruption is yet to be defined.

v2: Moved the CRC enable to link training init(Jani N)
v3: Moved crc enable to ddi pre enable 

Signed-off-by: Arun R Murthy 
---
 .../gpu/drm/i915/display/intel_dp_link_training.c| 12 
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c 
b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
index 3d3efcf02011..7064e465423b 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
@@ -1453,4 +1453,16 @@ void intel_dp_start_link_train(struct intel_dp *intel_dp,
 
if (!passed)
intel_dp_schedule_fallback_link_training(intel_dp, crtc_state);
+
+   /* DP v2.0 SCR on SDP CRC16 for 128b/132b Link Layer */
+   if (intel_dp_is_uhbr(crtc_state) && passed)
+   drm_dp_dpcd_writeb(_dp->aux,
+  DP_SDP_ERROR_DETECTION_CONFIGURATION,
+  DP_SDP_CRC16_128B132B_EN);
+   /*
+* VIDEO_DIP_CTL register bit 31 should be set to '0' to not
+* disable SDP CRC. This is applicable for Display version 13.
+* Default value of bit 31 is '0' hence discarding the write
+*/
+   /* TODO: Corrective actions on SDP corruption yet to be defined 
*/
 }
-- 
2.25.1