[PATCH 4/5] firewire: ohci: refactor local response packet handling

[Takashi Sakamoto]

For an asynchronous transaction to one of the two CSR address ranges on
the local node, the current implementation generates the packet data for
the response subaction internally while handling the request subaction.
The handling code is duplicated between the two ranges.

Reduce the duplication by moving response handling to the callers.

Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
---
 drivers/firewire/ohci.c | 54 ++++++++++++++++++++---------------------
 1 file changed, 26 insertions(+), 28 deletions(-)

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index ec069657ea8b..8a0aedf50a92 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1455,10 +1455,9 @@ static int handle_at_packet(struct context *context,
 
 static u32 get_cycle_time(struct fw_ohci *ohci);
 
-static void handle_local_rom(struct fw_ohci *ohci,
-			     struct fw_packet *packet, u32 csr)
+static void handle_local_rom(struct fw_ohci *ohci, struct fw_packet *packet, u32 csr,
+			     struct fw_packet *response)
 {
-	struct fw_packet response;
 	int tcode, rcode, length, i;
 	void *payload = NULL;
 
@@ -1480,17 +1479,12 @@ static void handle_local_rom(struct fw_ohci *ohci,
 		payload = (u8 *)ohci->config_rom + i;
 	}
 
-	fw_fill_response(&response, packet->header, rcode, payload, length);
-
-	// Timestamping on behalf of the hardware.
-	response.timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ohci));
-	fw_core_handle_response(&ohci->card, &response);
+	fw_fill_response(response, packet->header, rcode, payload, length);
 }
 
-static void handle_local_lock(struct fw_ohci *ohci,
-			      struct fw_packet *packet, u32 csr)
+static void handle_local_lock(struct fw_ohci *ohci, struct fw_packet *packet, u32 csr,
+			      struct fw_packet *response)
 {
-	struct fw_packet response;
 	int tcode, length, ext_tcode, sel, try;
 	__be32 *payload, lock_old;
 	u32 lock_arg, lock_data;
@@ -1508,9 +1502,8 @@ static void handle_local_lock(struct fw_ohci *ohci,
 		lock_arg = 0;
 		lock_data = 0;
 	} else {
-		fw_fill_response(&response, packet->header,
-				 RCODE_TYPE_ERROR, NULL, 0);
-		goto out;
+		fw_fill_response(response, packet->header, RCODE_TYPE_ERROR, NULL, 0);
+		return;
 	}
 
 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
@@ -1522,19 +1515,13 @@ static void handle_local_lock(struct fw_ohci *ohci,
 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
 			lock_old = cpu_to_be32(reg_read(ohci,
 							OHCI1394_CSRData));
-			fw_fill_response(&response, packet->header,
-					 RCODE_COMPLETE,
-					 &lock_old, sizeof(lock_old));
-			goto out;
+			fw_fill_response(response, packet->header, RCODE_COMPLETE, &lock_old,
+					 sizeof(lock_old));
+			return;
 		}
 
 	ohci_err(ohci, "swap not done (CSR lock timeout)\n");
-	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
-
- out:
-	// Timestamping on behalf of the hardware.
-	response.timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ohci));
-	fw_core_handle_response(&ohci->card, &response);
+	fw_fill_response(response, packet->header, RCODE_BUSY, NULL, 0);
 }
 
 static bool in_config_rom_csr_registers(u64 offset)
@@ -1560,10 +1547,21 @@ static void handle_local_request(struct at_context *ctx, struct fw_packet *packe
 
 	u64 csr_offset = async_header_get_offset(packet->header) - CSR_REGISTER_BASE;
 
-	if (in_config_rom_csr_registers(csr_offset)) {
-		handle_local_rom(ohci, packet, csr_offset);
-	} else if (in_bus_management_csr_registers(csr_offset)) {
-		handle_local_lock(ohci, packet, csr_offset);
+	if (in_config_rom_csr_registers(csr_offset) || in_bus_management_csr_registers(csr_offset)) {
+		struct fw_packet response;
+
+		memset(&response, 0, sizeof(response));
+
+		if (in_bus_management_csr_registers(csr_offset))
+			handle_local_lock(ohci, packet, csr_offset, &response);
+		else
+			handle_local_rom(ohci, packet, csr_offset, &response);
+
+		// Timestamping on behalf of the hardware.
+		response.timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ohci));
+
+		// Finish the transaction immediately.
+		fw_core_handle_response(&ohci->card, &response);
 	} else {
 		if (ctx == &ohci->at_request_ctx)
 			fw_core_handle_request(&ohci->card, packet);
-- 
2.53.0