[Intel-gfx] [PATCH v2] drm/i915/mst: only ack the ESI we actually handled

[Shankar, Uma]

> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Jani Nikula
> Sent: Thursday, January 20, 2022 4:31 PM
> To: Nikula, Jani <jani.nikula at intel.com>; intel-gfx at lists.freedesktop.org
> Subject: [Intel-gfx] [PATCH v2] drm/i915/mst: only ack the ESI we actually handled
> 
> Seems odd that we clear all event status indicators if we've only handled some. Only
> clear the ones we've handled.
> 
> v2: ack DOWN_REP and UP_REQ only if they were set in esi (Ville)

Looks Good to me.
Reviewed-by: Uma Shankar <uma.shankar at intel.com>

> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 20 ++++++++++++--------
>  1 file changed, 12 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 0960e6e3be77..cb726cee9e1d 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -3625,13 +3625,17 @@ static void intel_dp_handle_test_request(struct
> intel_dp *intel_dp)  }
> 
>  static void
> -intel_dp_mst_hpd_irq(struct intel_dp *intel_dp, u8 *esi, bool *handled)
> +intel_dp_mst_hpd_irq(struct intel_dp *intel_dp, u8 *esi, u8 *ack)
>  {
> -	drm_dp_mst_hpd_irq(&intel_dp->mst_mgr, esi, handled);
> +	bool handled = false;
> +
> +	drm_dp_mst_hpd_irq(&intel_dp->mst_mgr, esi, &handled);
> +	if (handled)
> +		ack[1] |= esi[1] & (DP_DOWN_REP_MSG_RDY |
> DP_UP_REQ_MSG_RDY);
> 
>  	if (esi[1] & DP_CP_IRQ) {
>  		intel_hdcp_handle_cp_irq(intel_dp->attached_connector);
> -		*handled = true;
> +		ack[1] |= DP_CP_IRQ;
>  	}
>  }
> 
> @@ -3683,7 +3687,7 @@ intel_dp_check_mst_status(struct intel_dp *intel_dp)
> 
>  	for (;;) {
>  		u8 esi[4] = {};
> -		bool handled;
> +		u8 ack[4] = {};
> 
>  		if (!intel_dp_get_sink_irq_esi(intel_dp, esi)) {
>  			drm_dbg_kms(&i915->drm,
> @@ -3699,15 +3703,15 @@ intel_dp_check_mst_status(struct intel_dp *intel_dp)
>  		    esi[3] & LINK_STATUS_CHANGED) {
>  			if (!intel_dp_mst_link_status(intel_dp))
>  				link_ok = false;
> -			handled = true;
> +			ack[3] |= LINK_STATUS_CHANGED;
>  		}
> 
> -		intel_dp_mst_hpd_irq(intel_dp, esi, &handled);
> +		intel_dp_mst_hpd_irq(intel_dp, esi, ack);
> 
> -		if (!handled)
> +		if (!memchr_inv(ack, 0, sizeof(ack)))
>  			break;
> 
> -		if (!intel_dp_ack_sink_irq_esi(intel_dp, esi))
> +		if (!intel_dp_ack_sink_irq_esi(intel_dp, ack))
>  			drm_dbg_kms(&i915->drm, "Failed to ack ESI\n");
>  	}
> 
> --
> 2.30.2