[PATCH 2/2] drm/i915/hdcp: fix intel_hdcp_get_repeater_ctl() error return value

[Ville Syrjälä]

On Tue, Dec 19, 2023 at 12:47:46PM +0200, Jani Nikula wrote:
> intel_hdcp_get_repeater_ctl() is supposed to return unsigned register
> contents. Returning negative error values is unexpected, and none of the
> callers check for that.
> 
> Sort of fix the error cases by returning 0. I don't think we should hit
> these cases anyway, and using 0 for the registers is safer than
> 0xffffffea (-EINVAL).
> 
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_hdcp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index f9010094ff29..ee29fcb860e4 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -347,7 +347,7 @@ u32 intel_hdcp_get_repeater_ctl(struct drm_i915_private *i915,
>  		default:
>  			drm_err(&i915->drm, "Unknown transcoder %d\n",
>  				cpu_transcoder);

These should probably be MISSING_CASE() as well.

Anyways,
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> -			return -EINVAL;
> +			return 0;
>  		}
>  	}
>  
> @@ -364,7 +364,7 @@ u32 intel_hdcp_get_repeater_ctl(struct drm_i915_private *i915,
>  		return HDCP_DDIE_REP_PRESENT | HDCP_DDIE_SHA1_M0;
>  	default:
>  		drm_err(&i915->drm, "Unknown port %d\n", port);
> -		return -EINVAL;
> +		return 0;
>  	}
>  }
>  
> -- 
> 2.39.2

-- 
Ville Syrjälä
Intel