[SRU][R][PATCH 17/22] drm/i915/dp: Read/ack sink count and sink IRQs for SST as it's done for MST
Werner Sembach
wse at tuxedocomputers.com
Tue Aug 4 22:18:43 UTC 2026
From: Imre Deak <imre.deak at intel.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.
v2: Document the ESI vector get/ack helper fnuctions' return value.
(Jani, Luca)
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Luca Coelho <luciano.coelho at intel.com>
Reviewed-by: Luca Coelho <luciano.coelho at intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
Link: https://patch.msgid.link/20260225164618.1261368-16-imre.deak@intel.com
Signed-off-by: Werner Sembach <wse at tuxedocomputers.com>
---
drivers/gpu/drm/i915/display/intel_dp.c | 142 +++++++++++++-----------
1 file changed, 79 insertions(+), 63 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 7728e5fe16473..76546b93ff988 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4844,6 +4844,76 @@ static bool intel_dp_ack_sink_irq_esi(struct intel_dp *intel_dp, u8 esi[4])
return false;
}
+/* Return %true if reading the ESI vector succeeded, %false otherwise. */
+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;
+}
+
+/* Return %true if acking the ESI vector IRQ events succeeded, %false otherwise. */
+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;
+}
+
+/*
+ * Return %true if reading the ESI vector and acking the ESI IRQ events succeeded,
+ * %false otherwise.
+ */
+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)
@@ -5664,31 +5734,6 @@ void intel_dp_check_link_state(struct intel_dp *intel_dp)
intel_encoder_link_check_queue_work(encoder, 0);
}
-/*
- * Return %true if a full connector reprobe is required due to a failure while
- * reading or acking the device service IRQs.
- */
-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);
@@ -5703,31 +5748,6 @@ 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");
}
-/* Return %true if reading and acking the link service IRQs succeeded. */
-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;
-}
/*
* Return %true if a full connector reprobe is required after handling a link
@@ -5769,30 +5789,26 @@ 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, irq_mask);
-
- if (!intel_dp_get_and_ack_link_service_irq(intel_dp, &irq_mask))
- return false;
+ intel_dp_handle_device_service_irq(intel_dp, esi[1]);
- 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 */
--
2.43.0
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