[PATCH] firmware: arm_scmi: add timeout in do_xfer_with_response()

[Matthew Bystrin <dev.mbstr@gmail.com>]

Add timeout argument to do_xfer_with_response() with subsequent changes
in corresponding drivers. To maintain backward compatibility use
previous hardcoded timeout value.

According to SCMI specification [1] there is no defined timeout for
delayed messages in the interface. While hardcoded 2 seconds timeout
might be good enough for existing protocol drivers, moving it to the
function argument may be useful for vendor-specific protocols with
different timing needs.

Link: https://developer.arm.com/Architectures/System%20Control%20and%20Management%20Interface
Signed-off-by: Matthew Bystrin <dev.mbstr@gmail.com>
---
 drivers/firmware/arm_scmi/clock.c     | 2 +-
 drivers/firmware/arm_scmi/common.h    | 1 -
 drivers/firmware/arm_scmi/driver.c    | 6 ++++--
 drivers/firmware/arm_scmi/powercap.c  | 2 +-
 drivers/firmware/arm_scmi/protocols.h | 3 ++-
 drivers/firmware/arm_scmi/reset.c     | 2 +-
 drivers/firmware/arm_scmi/sensors.c   | 4 ++--
 drivers/firmware/arm_scmi/voltage.c   | 2 +-
 include/linux/scmi_protocol.h         | 1 +
 9 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index 2ed2279388f0..4b5cd73384c3 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -596,7 +596,7 @@ static int scmi_clock_rate_set(const struct scmi_protocol_handle *ph,
 	cfg->value_high = cpu_to_le32(rate >> 32);
 
 	if (flags & CLOCK_SET_ASYNC) {
-		ret = ph->xops->do_xfer_with_response(ph, t);
+		ret = ph->xops->do_xfer_with_response(ph, t, SCMI_DEFAULT_TIMEOUT);
 		if (!ret) {
 			struct scmi_msg_resp_set_rate_complete *resp;
 
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 10ea7962323e..34527366c909 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -29,7 +29,6 @@
 
 #define SCMI_MAX_CHANNELS		256
 
-#define SCMI_MAX_RESPONSE_TIMEOUT	(2 * MSEC_PER_SEC)
 
 #define SCMI_SHMEM_MAX_PAYLOAD_SIZE	104
 
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 1c75a4c9c371..51c6634d5505 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -1490,6 +1490,7 @@ static void reset_rx_to_maxsz(const struct scmi_protocol_handle *ph,
  *
  * @ph: Pointer to SCMI protocol handle
  * @xfer: Transfer to initiate and wait for response
+ * @timeout_ms: Delayed response wait timeout, if unsure use SCMI_DEFAULT_TIMEOUT
  *
  * Using asynchronous commands in atomic/polling mode should be avoided since
  * it could cause long busy-waiting here, so ignore polling for the delayed
@@ -1509,9 +1510,10 @@ static void reset_rx_to_maxsz(const struct scmi_protocol_handle *ph,
  *	return corresponding error, else if all goes well, return 0.
  */
 static int do_xfer_with_response(const struct scmi_protocol_handle *ph,
-				 struct scmi_xfer *xfer)
+				 struct scmi_xfer *xfer, unsigned long timeout_ms)
 {
-	int ret, timeout = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT);
+	int ret;
+	unsigned long timeout = msecs_to_jiffies(timeout_ms);
 	DECLARE_COMPLETION_ONSTACK(async_response);
 
 	xfer->async_done = &async_response;
diff --git a/drivers/firmware/arm_scmi/powercap.c b/drivers/firmware/arm_scmi/powercap.c
index 1fa79bba492e..82565dacd301 100644
--- a/drivers/firmware/arm_scmi/powercap.c
+++ b/drivers/firmware/arm_scmi/powercap.c
@@ -386,7 +386,7 @@ static int scmi_powercap_xfer_cap_set(const struct scmi_protocol_handle *ph,
 	if (!pc->async_powercap_cap_set || ignore_dresp) {
 		ret = ph->xops->do_xfer(ph, t);
 	} else {
-		ret = ph->xops->do_xfer_with_response(ph, t);
+		ret = ph->xops->do_xfer_with_response(ph, t, SCMI_DEFAULT_TIMEOUT);
 		if (!ret) {
 			struct scmi_msg_resp_powercap_cap_set_complete *resp;
 
diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h
index aaee57cdcd55..b1e3cf3601fe 100644
--- a/drivers/firmware/arm_scmi/protocols.h
+++ b/drivers/firmware/arm_scmi/protocols.h
@@ -307,7 +307,8 @@ struct scmi_xfer_ops {
 	int (*do_xfer)(const struct scmi_protocol_handle *ph,
 		       struct scmi_xfer *xfer);
 	int (*do_xfer_with_response)(const struct scmi_protocol_handle *ph,
-				     struct scmi_xfer *xfer);
+				     struct scmi_xfer *xfer,
+				     unsigned long timeout_ms);
 	void (*xfer_put)(const struct scmi_protocol_handle *ph,
 			 struct scmi_xfer *xfer);
 };
diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c
index 0aa82b96f41b..a458b1c16c51 100644
--- a/drivers/firmware/arm_scmi/reset.c
+++ b/drivers/firmware/arm_scmi/reset.c
@@ -198,7 +198,7 @@ static int scmi_domain_reset(const struct scmi_protocol_handle *ph, u32 domain,
 	dom->reset_state = cpu_to_le32(state);
 
 	if (flags & ASYNCHRONOUS_RESET)
-		ret = ph->xops->do_xfer_with_response(ph, t);
+		ret = ph->xops->do_xfer_with_response(ph, t, SCMI_DEFAULT_TIMEOUT);
 	else
 		ret = ph->xops->do_xfer(ph, t);
 
diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
index 791efd0f82d7..9a07399237f5 100644
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -871,7 +871,7 @@ static int scmi_sensor_reading_get(const struct scmi_protocol_handle *ph,
 	s = si->sensors + sensor_id;
 	if (s->async) {
 		sensor->flags = cpu_to_le32(SENSOR_READ_ASYNC);
-		ret = ph->xops->do_xfer_with_response(ph, t);
+		ret = ph->xops->do_xfer_with_response(ph, t, SCMI_DEFAULT_TIMEOUT);
 		if (!ret) {
 			struct scmi_resp_sensor_reading_complete *resp;
 
@@ -943,7 +943,7 @@ scmi_sensor_reading_get_timestamped(const struct scmi_protocol_handle *ph,
 	sensor->id = cpu_to_le32(sensor_id);
 	if (s->async) {
 		sensor->flags = cpu_to_le32(SENSOR_READ_ASYNC);
-		ret = ph->xops->do_xfer_with_response(ph, t);
+		ret = ph->xops->do_xfer_with_response(ph, t, SCMI_DEFAULT_TIMEOUT);
 		if (!ret) {
 			int i;
 			struct scmi_resp_sensor_reading_complete_v3 *resp;
diff --git a/drivers/firmware/arm_scmi/voltage.c b/drivers/firmware/arm_scmi/voltage.c
index fda6a1573609..26b1f034256b 100644
--- a/drivers/firmware/arm_scmi/voltage.c
+++ b/drivers/firmware/arm_scmi/voltage.c
@@ -348,7 +348,7 @@ static int scmi_voltage_level_set(const struct scmi_protocol_handle *ph,
 		ret = ph->xops->do_xfer(ph, t);
 	} else {
 		cmd->flags = cpu_to_le32(0x1);
-		ret = ph->xops->do_xfer_with_response(ph, t);
+		ret = ph->xops->do_xfer_with_response(ph, t, SCMI_DEFAULT_TIMEOUT);
 		if (!ret) {
 			struct scmi_resp_voltage_level_set_complete *resp;
 
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 688466a0e816..2426daae8a87 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -16,6 +16,7 @@
 #define SCMI_MAX_STR_SIZE		64
 #define SCMI_SHORT_NAME_MAX_SIZE	16
 #define SCMI_MAX_NUM_RATES		16
+#define SCMI_DEFAULT_TIMEOUT		(2 * MSEC_PER_SEC)
 
 /**
  * struct scmi_revision_info - version information structure
-- 
2.47.2