[PATCH v2 15/20] drm/i915/dp: Read/ack sink count and sink IRQs for SST as it's done for MST

[Imre Deak <imre.deak@intel.com>]

From: Imre Deak <imre.deak@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.deak@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 6156fd91b13c5..749bcb4dfe4e7 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4952,6 +4952,70 @@ 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;
+}
+
 bool
 intel_dp_needs_vsc_sdp(const struct intel_crtc_state *crtc_state,
 		       const struct drm_connector_state *conn_state)
@@ -5772,27 +5836,6 @@ 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);
@@ -5807,31 +5850,6 @@ 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);
@@ -5868,30 +5886,26 @@ 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 */
-- 
2.49.1