Re: [PATCH] drm/i915/hdcp: Use correct cp_irq_count

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 8/9/2024 5:11 PM, Suraj Kandpal wrote:
> We are checking cp_irq_count from the wrong hdcp structure which
> ends up giving timed out errors. We only increment the cp_irq_count
> of the primary connector's hdcp structure but here in case of
> multidisplay setup we end up checking the secondary connector's hdcp
> structure, which will not have its cp_irq_count incremented. This leads
> to a timed out at CP_IRQ error even though a CP_IRQ was raised. Extract
> it from the correct intel_hdcp structure.

It would be good to have helpers to get the correct hdcp structure based 
on the context, perhaps as part of a separate series.

In any case, the change looks good to me.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>


>
> --v2
> -Explain why it was the wrong hdcp structure [Jani]
>
> Fixes: 8c9e4f68b861 ("drm/i915/hdcp: Use per-device debugs")
> Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> index ec357d2670f1..3425b3643143 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> @@ -39,7 +39,9 @@ static u32 transcoder_to_stream_enc_status(enum transcoder cpu_transcoder)
>   static void intel_dp_hdcp_wait_for_cp_irq(struct intel_connector *connector,
>   					  int timeout)
>   {
> -	struct intel_hdcp *hdcp = &connector->hdcp;
> +	struct intel_digital_port *dig_port = intel_attached_dig_port(connector);
> +	struct intel_dp *dp = &dig_port->dp;
> +	struct intel_hdcp *hdcp = &dp->attached_connector->hdcp;
>   	long ret;
>   
>   #define C (hdcp->cp_irq_count_cached != atomic_read(&hdcp->cp_irq_count))