6 files changed, 15 insertions, 11 deletions
diff --git a/drivers/platform/surface/aggregator/Kconfig b/drivers/platform/surface/aggregator/Kconfig
index 88afc38ffdc5..957c216c180c 100644
--- a/drivers/platform/surface/aggregator/Kconfig
+++ b/drivers/platform/surface/aggregator/Kconfig
@@ -5,7 +5,7 @@ menuconfig SURFACE_AGGREGATOR
 	tristate "Microsoft Surface System Aggregator Module Subsystem and Drivers"
 	depends on SERIAL_DEV_BUS
 	depends on ACPI && !RISCV
-	select CRC_CCITT
+	select CRC_ITU_T
 	help
 	  The Surface System Aggregator Module (Surface SAM or SSAM) is an
 	  embedded controller (EC) found on 5th- and later-generation Microsoft
diff --git a/drivers/platform/surface/aggregator/bus.c b/drivers/platform/surface/aggregator/bus.c
index 42ccd7f1c9b9..118caa651bec 100644
--- a/drivers/platform/surface/aggregator/bus.c
+++ b/drivers/platform/surface/aggregator/bus.c
@@ -35,6 +35,8 @@ static struct attribute *ssam_device_attrs[] = {
 };
 ATTRIBUTE_GROUPS(ssam_device);
 
+static const struct bus_type ssam_bus_type;
+
 static int ssam_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
 {
 	const struct ssam_device *sdev = to_ssam_device(dev);
@@ -329,13 +331,12 @@ static void ssam_bus_remove(struct device *dev)
 		sdrv->remove(to_ssam_device(dev));
 }
 
-struct bus_type ssam_bus_type = {
+static const struct bus_type ssam_bus_type = {
 	.name   = "surface_aggregator",
 	.match  = ssam_bus_match,
 	.probe  = ssam_bus_probe,
 	.remove = ssam_bus_remove,
 };
-EXPORT_SYMBOL_GPL(ssam_bus_type);
 
 /**
  * __ssam_device_driver_register() - Register a SSAM client device driver.
diff --git a/drivers/platform/surface/aggregator/controller.h b/drivers/platform/surface/aggregator/controller.h
index f0d987abc51e..f1638c2081e8 100644
--- a/drivers/platform/surface/aggregator/controller.h
+++ b/drivers/platform/surface/aggregator/controller.h
@@ -238,8 +238,8 @@ struct ssam_controller {
  * layer of the controller has been shut down, %-ESHUTDOWN.
  */
 static inline
-int ssam_controller_receive_buf(struct ssam_controller *ctrl,
-				const unsigned char *buf, size_t n)
+ssize_t ssam_controller_receive_buf(struct ssam_controller *ctrl, const u8 *buf,
+				    size_t n)
 {
 	return ssh_ptl_rx_rcvbuf(&ctrl->rtl.ptl, buf, n);
 }
diff --git a/drivers/platform/surface/aggregator/core.c b/drivers/platform/surface/aggregator/core.c
index 1a6373dea109..9591a28bc38a 100644
--- a/drivers/platform/surface/aggregator/core.c
+++ b/drivers/platform/surface/aggregator/core.c
@@ -227,13 +227,16 @@ EXPORT_SYMBOL_GPL(ssam_client_bind);
 
 /* -- Glue layer (serdev_device -> ssam_controller). ------------------------ */
 
-static int ssam_receive_buf(struct serdev_device *dev, const unsigned char *buf,
-			    size_t n)
+static ssize_t ssam_receive_buf(struct serdev_device *dev, const u8 *buf,
+				size_t n)
 {
 	struct ssam_controller *ctrl;
+	int ret;
 
 	ctrl = serdev_device_get_drvdata(dev);
-	return ssam_controller_receive_buf(ctrl, buf, n);
+	ret = ssam_controller_receive_buf(ctrl, buf, n);
+
+	return ret < 0 ? 0 : ret;
 }
 
 static void ssam_write_wakeup(struct serdev_device *dev)
diff --git a/drivers/platform/surface/aggregator/ssh_packet_layer.c b/drivers/platform/surface/aggregator/ssh_packet_layer.c
index def8d7ac541f..d726b1a86319 100644
--- a/drivers/platform/surface/aggregator/ssh_packet_layer.c
+++ b/drivers/platform/surface/aggregator/ssh_packet_layer.c
@@ -1887,9 +1887,9 @@ int ssh_ptl_rx_stop(struct ssh_ptl *ptl)
  * Return: Returns the number of bytes transferred (positive or zero) on
  * success. Returns %-ESHUTDOWN if the packet layer has been shut down.
  */
-int ssh_ptl_rx_rcvbuf(struct ssh_ptl *ptl, const u8 *buf, size_t n)
+ssize_t ssh_ptl_rx_rcvbuf(struct ssh_ptl *ptl, const u8 *buf, size_t n)
 {
-	int used;
+	size_t used;
 
 	if (test_bit(SSH_PTL_SF_SHUTDOWN_BIT, &ptl->state))
 		return -ESHUTDOWN;
diff --git a/drivers/platform/surface/aggregator/ssh_packet_layer.h b/drivers/platform/surface/aggregator/ssh_packet_layer.h
index 64633522f971..c80e822070df 100644
--- a/drivers/platform/surface/aggregator/ssh_packet_layer.h
+++ b/drivers/platform/surface/aggregator/ssh_packet_layer.h
@@ -162,7 +162,7 @@ void ssh_ptl_shutdown(struct ssh_ptl *ptl);
 int ssh_ptl_submit(struct ssh_ptl *ptl, struct ssh_packet *p);
 void ssh_ptl_cancel(struct ssh_packet *p);
 
-int ssh_ptl_rx_rcvbuf(struct ssh_ptl *ptl, const u8 *buf, size_t n);
+ssize_t ssh_ptl_rx_rcvbuf(struct ssh_ptl *ptl, const u8 *buf, size_t n);
 
 /**
  * ssh_ptl_tx_wakeup_transfer() - Wake up packet transmitter thread for