[Intel-gfx] [PATCH] drm/i915: Don't skip debug messages when dp link config fails

[Matt Roper]

On Wed, Sep 25, 2019 at 10:39:32AM -0700, Matt Roper wrote:
> If we don't have enough link bandwidth to support the requested mode, we
> bail out of intel_dp_compute_link_config() early before the point it
> prints the helpful debug messages containing the available/necessary
> link bandwidth.  Since failures are when these messages are most useful,
> let the function proceed with printing those out and then just return
> the proper error code at the end.
> 
> Cc: Manasi Navare <manasi.d.navare at intel.com>
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>

Actually, disregard this patch for now; on errors we'd want to be
printing the lane counts and such from limits rather than pipe_config
which only gets locked in if we find a successful match.  This needs a
few more tweaks to be useful.


Matt

> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index e38db7278cf2..4a1f1d0298c2 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2083,12 +2083,9 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
>  
>  	/* enable compression if the mode doesn't fit available BW */
>  	DRM_DEBUG_KMS("Force DSC en = %d\n", intel_dp->force_dsc_en);
> -	if (ret || intel_dp->force_dsc_en) {
> +	if (ret || intel_dp->force_dsc_en)
>  		ret = intel_dp_dsc_compute_config(intel_dp, pipe_config,
>  						  conn_state, &limits);
> -		if (ret < 0)
> -			return ret;
> -	}
>  
>  	if (pipe_config->dsc_params.compression_enable) {
>  		DRM_DEBUG_KMS("DP lane count %d clock %d Input bpp %d Compressed bpp %d\n",
> @@ -2112,7 +2109,7 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
>  			      intel_dp_max_data_rate(pipe_config->port_clock,
>  						     pipe_config->lane_count));
>  	}
> -	return 0;
> +	return ret;
>  }
>  
>  static int
> -- 
> 2.21.0
> 

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation
(916) 356-2795