soundwire: cadence: further simplify low-level xfer_msg_defer() callback

The message pointer is already stored in the bus->defer structure, not
need to pass it as an argument.

Suggested-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20230119073211.85979-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: plbossart

drivers/soundwire/bus.c

@@ -237,7 +237,7 @@ static inline int do_transfer_defer(struct sdw_bus *bus,
 	init_completion(&defer->complete);
 
 	for (i = 0; i <= retry; i++) {
-		resp = bus->ops->xfer_msg_defer(bus, msg);
+		resp = bus->ops->xfer_msg_defer(bus);
 		ret = find_response_code(resp);
 		/* if cmd is ok or ignored return */
 		if (ret == 0 || ret == -ENODATA)

drivers/soundwire/cadence_master.c

@@ -749,10 +749,11 @@ cdns_xfer_msg(struct sdw_bus *bus, struct sdw_msg *msg)
 EXPORT_SYMBOL(cdns_xfer_msg);
 
 enum sdw_command_response
-cdns_xfer_msg_defer(struct sdw_bus *bus,
-		    struct sdw_msg *msg)
+cdns_xfer_msg_defer(struct sdw_bus *bus)
 {
 	struct sdw_cdns *cdns = bus_to_cdns(bus);
+	struct sdw_defer *defer = &bus->defer_msg;
+	struct sdw_msg *msg = defer->msg;
 	int cmd = 0, ret;
 
 	/* for defer only 1 message is supported */

drivers/soundwire/cadence_master.h

@@ -184,7 +184,7 @@ enum sdw_command_response
 cdns_xfer_msg(struct sdw_bus *bus, struct sdw_msg *msg);
 
 enum sdw_command_response
-cdns_xfer_msg_defer(struct sdw_bus *bus, struct sdw_msg *msg);
+cdns_xfer_msg_defer(struct sdw_bus *bus);
 
 u32 cdns_read_ping_status(struct sdw_bus *bus);
 

include/linux/soundwire/sdw.h

@@ -837,7 +837,8 @@ struct sdw_defer {
  * @read_prop: Read Master properties
  * @override_adr: Override value read from firmware (quirk for buggy firmware)
  * @xfer_msg: Transfer message callback
- * @xfer_msg_defer: Defer version of transfer message callback
+ * @xfer_msg_defer: Defer version of transfer message callback. The message is handled with the
+ * bus struct @sdw_defer
  * @set_bus_conf: Set the bus configuration
  * @pre_bank_switch: Callback for pre bank switch
  * @post_bank_switch: Callback for post bank switch
@@ -851,7 +852,7 @@ struct sdw_master_ops {
 	enum sdw_command_response (*xfer_msg)
 			(struct sdw_bus *bus, struct sdw_msg *msg);
 	enum sdw_command_response (*xfer_msg_defer)
-			(struct sdw_bus *bus, struct sdw_msg *msg);
+			(struct sdw_bus *bus);
 	int (*set_bus_conf)(struct sdw_bus *bus,
 			struct sdw_bus_params *params);
 	int (*pre_bank_switch)(struct sdw_bus *bus);