Implements the
Waitqueue is created to wait for CP_IRQ
Signaling the CP_IRQ arrival through atomic variable.
For applicable DP HDCP2.2 msgs read wait for CP_IRQ.
As per HDCP2.2 spec "HDCP Transmitters must process CP_IRQ interrupts
when they are received from HDCP Receivers"
Without CP_IRQ processing, DP HDCP2.2 H_Prime msg was getting corrupted
while reading it based on corresponding status bit. This creates the
random failures in reading the DP HDCP2.2 msgs.
v2:
CP_IRQ arrival is tracked based on the atomic val inc [daniel]
Recording the reviewed-by Daniel from IRC.
Signed-off-by: Ramalingam C <ramalingam.c@xxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
---
drivers/gpu/drm/i915/intel_dp.c | 31 +++++++++++++++++++++++--------
drivers/gpu/drm/i915/intel_drv.h | 8 ++++++++
drivers/gpu/drm/i915/intel_hdcp.c | 11 ++++-------
3 files changed, 35 insertions(+), 15 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index e9fe25f21200..e1a051c0fbfe 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -5623,6 +5623,18 @@ void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder)
edp_panel_vdd_off_sync(intel_dp);
}
+static void intel_dp_hdcp_wait_for_cp_irq(struct intel_hdcp *hdcp, int timeout)
+{
+ long ret;
+
+#define C (hdcp->cp_irq_count_cached != atomic_read(&hdcp->cp_irq_count))
+ ret = wait_event_interruptible_timeout(hdcp->cp_irq_queue, C,
+ msecs_to_jiffies(timeout));
+
+ if (!ret)
+ DRM_DEBUG_KMS("Timedout at waiting for CP_IRQ\n");
+}
+
static
int intel_dp_hdcp_write_an_aksv(struct intel_digital_port *intel_dig_port,
u8 *an)
@@ -5967,14 +5979,13 @@ intel_dp_hdcp2_wait_for_msg(struct intel_digital_port *intel_dig_port,
mdelay(timeout);
ret = 0;
} else {
- /* TODO: In case if you need to wait on CP_IRQ, do it here */
- ret = __wait_for(ret =
- hdcp2_detect_msg_availability(intel_dig_port,
- msg_id,
- &msg_ready),
- !ret && msg_ready, timeout * 1000,
- 1000, 5 * 1000);
-
+ /*
+ * As we want to check the msg availability at timeout, Ignoring
+ * the timeout at wait for CP_IRQ.
+ */
+ intel_dp_hdcp_wait_for_cp_irq(hdcp, timeout);
+ ret = hdcp2_detect_msg_availability(intel_dig_port,
+ msg_id, &msg_ready);
if (!msg_ready)
ret = -ETIMEDOUT;
}
@@ -6001,6 +6012,8 @@ static
int intel_dp_hdcp2_write_msg(struct intel_digital_port *intel_dig_port,
void *buf, size_t size)
{
+ struct intel_dp *dp = &intel_dig_port->dp;
+ struct intel_hdcp *hdcp = &dp->attached_connector->hdcp;
unsigned int offset;
u8 *byte = buf;
ssize_t ret, bytes_to_write, len;
@@ -6016,6 +6029,8 @@ int intel_dp_hdcp2_write_msg(struct intel_digital_port *intel_dig_port,
bytes_to_write = size - 1;
byte++;
+ hdcp->cp_irq_count_cached = atomic_read(&hdcp->cp_irq_count);
+
while (bytes_to_write) {
len = bytes_to_write > DP_AUX_MAX_PAYLOAD_BYTES ?
DP_AUX_MAX_PAYLOAD_BYTES : bytes_to_write;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 94ee36c28e9a..241e422d46e3 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -474,6 +474,14 @@ struct intel_hdcp {
* over re-Auth has to be triggered.
*/
u32 seq_num_m;
+
+ /*
+ * Work queue to signal the CP_IRQ. Used for the waiters to read the
+ * available information from HDCP DP sink.
+ */
+ wait_queue_head_t cp_irq_queue;
+ atomic_t cp_irq_count;
+ int cp_irq_count_cached;
};
struct intel_connector {
diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
index fe0445c0eaac..6178fe93f398 100644
--- a/drivers/gpu/drm/i915/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -1806,6 +1806,7 @@ int intel_hdcp_init(struct intel_connector *connector,
if (is_hdcp2_supported(dev_priv))
intel_hdcp2_init(connector);
+ init_waitqueue_head(&hdcp->cp_irq_queue);
return 0;
}
@@ -1935,12 +1936,8 @@ void intel_hdcp_handle_cp_irq(struct intel_connector *connector)
if (!hdcp->shim)
return;
- /*
- * CP_IRQ could be triggered due to 1. HDCP2.2 auth msgs availability,
- * 2. link failure and 3. repeater reauth request. At present we dont
- * handle the CP_IRQ for the HDCP2.2 auth msg availability for read.
- * To handle other two causes for CP_IRQ we have the work_fn which is
- * scheduled here.
- */
+ atomic_inc(&connector->hdcp.cp_irq_count);
+ wake_up_all(&connector->hdcp.cp_irq_queue);
+
schedule_delayed_work(&hdcp->check_work, 0);
}
--
2.7.4
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