Re: [PATCH 03/12] drm/i915/dp: Separate out helper for compute fec_enable

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 20 Nov 2024, Ankit Nautiyal <ankit.k.nautiyal@intel.com> wrote:
> Make a separate function for setting fec_enable in crtc_state.
> Drop the check for FEC support as its already checked while checking for
> DSC support.

That's two changes that generally shouldn't be bundled together.

Aim for separating non-functional refactoring and functional
changes. (Well, arguably dropping the FEC check should also be
non-functional, but you know what I mean.)

> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 30 +++++++++++++++++--------
>  1 file changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index dee15a05e7fd..d82e25d0dc5a 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2352,6 +2352,26 @@ static int intel_edp_dsc_compute_pipe_bpp(struct intel_dp *intel_dp,
>  	return 0;
>  }
>  
> +static void intel_dp_compute_fec_config(struct intel_dp *intel_dp,
> +					struct intel_crtc_state *pipe_config)

I think all encoder->callback_name hooks should be named
something_something_callback_name(), and the same goes for helpers
specifically aimed at this.

This would make the function intel_dp_fec_compute_config().

Yes, in many ways "compute fec config" reads better, but there's value
in being able to search for "_compute_config", and to know this is only
for he ->compute_config path.

BR,
Jani.


> +{
> +	if (pipe_config->fec_enable)
> +		return;
> +
> +	/*
> +	 * Though eDP v1.5 supports FEC with DSC, unlike DP, it is optional.
> +	 * Since, FEC is a bandwidth overhead, continue to not enable it for
> +	 * eDP. Until, there is a good reason to do so.
> +	 */
> +	if (intel_dp_is_edp(intel_dp))
> +		return;
> +
> +	if (intel_dp_is_uhbr(pipe_config))
> +		return;
> +
> +	pipe_config->fec_enable = true;
> +}
> +
>  int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
>  				struct intel_crtc_state *pipe_config,
>  				struct drm_connector_state *conn_state,
> @@ -2368,15 +2388,7 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
>  	int num_joined_pipes = intel_crtc_num_joined_pipes(pipe_config);
>  	int ret;
>  
> -	/*
> -	 * Though eDP v1.5 supports FEC with DSC, unlike DP, it is optional.
> -	 * Since, FEC is a bandwidth overhead, continue to not enable it for
> -	 * eDP. Until, there is a good reason to do so.
> -	 */
> -	pipe_config->fec_enable = pipe_config->fec_enable ||
> -		(!intel_dp_is_edp(intel_dp) &&
> -		 intel_dp_supports_fec(intel_dp, connector, pipe_config) &&
> -		 !intel_dp_is_uhbr(pipe_config));
> +	intel_dp_compute_fec_config(intel_dp, pipe_config);
>  
>  	if (!intel_dp_dsc_supports_format(connector, pipe_config->output_format))
>  		return -EINVAL;

-- 
Jani Nikula, Intel