On Thu, 2025-06-26 at 11:20 +0300, Imre Deak wrote:
> From: Imre Deak <imre.d...@gmail.com>
>
> Read and ack the sink count, sink device and link service IRQs for SST
> the same way this is done for MST, the read/ack happening in separate
> steps via an ESI (Event Status Indicator) vector.
>
> The above way is more efficient, since on newer (DPCD_REV >= 1.2) sinks
> the DP_SINK_COUNT_ESI..DP_LINK_SERVICE_IRQ_VECTOR_ESI0 registers can be
> read out in one AUX transaction - and the 3 last one written in one
> transaction. Also this allows sharing more of the SST and MST IRQ
> handling code (done as a follow-up).
>
> For now keep the current behavior of always reading the legacy
> DP_SINK_COUNT, DP_DEVICE_SERVICE_IRQ_VECTOR registers and not reading
> the DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1 register.
>
> Signed-off-by: Imre Deak <imre.d...@gmail.com>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 132 +++++++++++++-----------
> 1 file changed, 73 insertions(+), 59 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 2ba4a810f22c2..2e6ed7d2a64a6 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4573,6 +4573,70 @@ static bool intel_dp_ack_sink_irq_esi(struct intel_dp
> *intel_dp, u8 esi[4])
> return false;
> }
>
> +static bool intel_dp_get_sink_irq_esi_sst(struct intel_dp *intel_dp, u8
> esi[4])
> +{
> + memset(esi, 0, 4);
> +
> + /*
> + * TODO: For DP_DPCD_REV >= 0x12 read
> + * DP_SINK_COUNT_ESI and DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0.
> + */
> + if (drm_dp_dpcd_read_data(&intel_dp->aux, DP_SINK_COUNT, esi, 2) != 0)
> + return false;
> +
> + if (intel_dp->dpcd[DP_DPCD_REV] < DP_DPCD_REV_12)
> + return true;
> +
> + /* TODO: Read DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1 as well */
> + if (drm_dp_dpcd_read_byte(&intel_dp->aux,
> DP_LINK_SERVICE_IRQ_VECTOR_ESI0, &esi[3]) != 0)
> + return false;
> +
> + return true;
> +}
> +
> +static bool intel_dp_ack_sink_irq_esi_sst(struct intel_dp *intel_dp, u8
> esi[4])
> +{
> + /*
> + * TODO: For DP_DPCD_REV >= 0x12 write
> + * DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0
> + */
> + if (drm_dp_dpcd_write_byte(&intel_dp->aux,
> DP_DEVICE_SERVICE_IRQ_VECTOR, esi[1]) != 0)
> + return false;
> +
> + if (intel_dp->dpcd[DP_DPCD_REV] < DP_DPCD_REV_12)
> + return true;
> +
> + /* TODO: Read DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1 as well */
> + if (drm_dp_dpcd_write_byte(&intel_dp->aux,
> DP_LINK_SERVICE_IRQ_VECTOR_ESI0, esi[3]) != 0)
> + return false;
> +
> + return true;
> +}
> +
> +static bool intel_dp_get_and_ack_sink_irq_esi_sst(struct intel_dp *intel_dp,
> u8 esi[4])
> +{
> + struct intel_display *display = to_intel_display(intel_dp);
> + struct intel_connector *connector = intel_dp->attached_connector;
> + struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
> +
> + if (!intel_dp_get_sink_irq_esi_sst(intel_dp, esi))
> + return false;
> +
> + drm_dbg_kms(display->drm,
> + "[CONNECTOR:%d:%s][ENCODER:%d:%s] DPRX ESI: %4ph\n",
> + connector->base.base.id, connector->base.name,
> + encoder->base.base.id, encoder->base.name,
> + esi);
> +
> + if (mem_is_zero(&esi[1], 3))
> + return true;
> +
> + if (!intel_dp_ack_sink_irq_esi_sst(intel_dp, esi))
> + return false;
> +
> + return true;
> +}
> +
Again, I think it's better to propagate the error than to swallow it
and return a bool.
Other than that, it looks good to me. So if you agree with this
change:
Reviewed-by: Luca Coelho <luciano.coe...@tintel.com>
--
Cheers,
Luca.
> @@ -5393,27 +5457,6 @@ void intel_dp_check_link_state(struct intel_dp
> *intel_dp)
> intel_encoder_link_check_queue_work(encoder, 0);
> }
>
> -static bool intel_dp_get_and_ack_device_service_irq(struct intel_dp
> *intel_dp, u8 *irq_mask)
> -{
> - u8 val;
> -
> - *irq_mask = 0;
> -
> - if (drm_dp_dpcd_readb(&intel_dp->aux,
> - DP_DEVICE_SERVICE_IRQ_VECTOR, &val) != 1)
> - return false;
> -
> - if (!val)
> - return true;
> -
> - if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_DEVICE_SERVICE_IRQ_VECTOR,
> val) != 1)
> - return false;
> -
> - *irq_mask = val;
> -
> - return true;
> -}
> -
> static void intel_dp_handle_device_service_irq(struct intel_dp *intel_dp, u8
> irq_mask)
> {
> struct intel_display *display = to_intel_display(intel_dp);
> @@ -5428,31 +5471,6 @@ static void intel_dp_handle_device_service_irq(struct
> intel_dp *intel_dp, u8 irq
> drm_dbg_kms(display->drm, "Sink specific irq unhandled\n");
> }
>
> -static bool intel_dp_get_and_ack_link_service_irq(struct intel_dp *intel_dp,
> u8 *irq_mask)
> -{
> - u8 val;
> -
> - *irq_mask = 0;
> -
> - if (intel_dp->dpcd[DP_DPCD_REV] < DP_DPCD_REV_12)
> - return true;
> -
> - if (drm_dp_dpcd_readb(&intel_dp->aux,
> - DP_LINK_SERVICE_IRQ_VECTOR_ESI0, &val) != 1)
> - return false;
> -
> - if (!val)
> - return true;
> -
> - if (drm_dp_dpcd_writeb(&intel_dp->aux,
> - DP_LINK_SERVICE_IRQ_VECTOR_ESI0, val) != 1)
> - return false;
> -
> - *irq_mask = val;
> -
> - return true;
> -}
> -
> static bool intel_dp_handle_link_service_irq(struct intel_dp *intel_dp, u8
> irq_mask)
> {
> struct intel_display *display = to_intel_display(intel_dp);
> @@ -5489,30 +5507,26 @@ static bool
> intel_dp_short_pulse(struct intel_dp *intel_dp)
> {
> bool reprobe_needed = false;
> - u8 irq_mask;
> + u8 esi[4] = {};
>
> intel_dp_test_reset(intel_dp);
>
> + if (!intel_dp_get_and_ack_sink_irq_esi_sst(intel_dp, esi))
> + return false;
> +
> /*
> - * Now read the DPCD to see if it's actually running
> * If the current value of sink count doesn't match with
> - * the value that was stored earlier or dpcd read failed
> - * we need to do full detection
> + * the value that was stored earlier we need to do full
> + * detection.
> */
> if (intel_dp_has_sink_count(intel_dp) &&
> - drm_dp_read_sink_count(&intel_dp->aux) != intel_dp->sink_count)
> + DP_GET_SINK_COUNT(esi[0]) != intel_dp->sink_count)
> /* No need to proceed if we are going to do full detect */
> return false;
>
> - if (!intel_dp_get_and_ack_device_service_irq(intel_dp, &irq_mask))
> - return false;
> + intel_dp_handle_device_service_irq(intel_dp, esi[1]);
>
> - intel_dp_handle_device_service_irq(intel_dp, irq_mask);
> -
> - if (!intel_dp_get_and_ack_link_service_irq(intel_dp, &irq_mask))
> - return false;
> -
> - if (intel_dp_handle_link_service_irq(intel_dp, irq_mask))
> + if (intel_dp_handle_link_service_irq(intel_dp, esi[3]))
> reprobe_needed = true;
>
> /* Handle CEC interrupts, if any */
