V4L/DVB (13410): firedtv: remove an unnecessary function argument

All read transactions initiated by firedtv are only quadlet-sized, hence
the backend->read call can be simplified a little.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/firewire/firedtv-1394.c

@@ -101,9 +101,9 @@ static int node_lock(struct firedtv *fdtv, u64 addr, __be32 data[])
 	return ret;
 }
 
-static int node_read(struct firedtv *fdtv, u64 addr, void *data, size_t len)
+static int node_read(struct firedtv *fdtv, u64 addr, void *data)
 {
-	return hpsb_node_read(node_of(fdtv), addr, data, len);
+	return hpsb_node_read(node_of(fdtv), addr, data, 4);
 }
 
 static int node_write(struct firedtv *fdtv, u64 addr, void *data, size_t len)

drivers/media/dvb/firewire/firedtv-avc.c

@@ -1236,14 +1236,14 @@ int avc_ca_get_mmi(struct firedtv *fdtv, char *mmi_object, unsigned int *len)
 
 #define CMP_OUTPUT_PLUG_CONTROL_REG_0	0xfffff0000904ULL
 
-static int cmp_read(struct firedtv *fdtv, void *buf, u64 addr, size_t len)
+static int cmp_read(struct firedtv *fdtv, u64 addr, __be32 *data)
 {
 	int ret;
 
 	if (mutex_lock_interruptible(&fdtv->avc_mutex))
 		return -EINTR;
 
-	ret = fdtv->backend->read(fdtv, addr, buf, len);
+	ret = fdtv->backend->read(fdtv, addr, data);
 	if (ret < 0)
 		dev_err(fdtv->device, "CMP: read I/O error\n");
 
@@ -1293,7 +1293,7 @@ int cmp_establish_pp_connection(struct firedtv *fdtv, int plug, int channel)
 	int attempts = 0;
 	int ret;
 
-	ret = cmp_read(fdtv, opcr, opcr_address, 4);
+	ret = cmp_read(fdtv, opcr_address, opcr);
 	if (ret < 0)
 		return ret;
 
@@ -1357,7 +1357,7 @@ void cmp_break_pp_connection(struct firedtv *fdtv, int plug, int channel)
 	u64 opcr_address = CMP_OUTPUT_PLUG_CONTROL_REG_0 + (plug << 2);
 	int attempts = 0;
 
-	if (cmp_read(fdtv, opcr, opcr_address, 4) < 0)
+	if (cmp_read(fdtv, opcr_address, opcr) < 0)
 		return;
 
 repeat:

drivers/media/dvb/firewire/firedtv-fw.c

@@ -46,10 +46,9 @@ static int node_lock(struct firedtv *fdtv, u64 addr, __be32 data[])
 	return node_req(fdtv, addr, data, 8, TCODE_LOCK_COMPARE_SWAP);
 }
 
-static int node_read(struct firedtv *fdtv, u64 addr, void *data, size_t len)
+static int node_read(struct firedtv *fdtv, u64 addr, void *data)
 {
-	return node_req(fdtv, addr, data, len, len == 4 ?
-			TCODE_READ_QUADLET_REQUEST : TCODE_READ_BLOCK_REQUEST);
+	return node_req(fdtv, addr, data, 4, TCODE_READ_QUADLET_REQUEST);
 }
 
 static int node_write(struct firedtv *fdtv, u64 addr, void *data, size_t len)

drivers/media/dvb/firewire/firedtv.h

@@ -74,7 +74,7 @@ struct firedtv;
 
 struct firedtv_backend {
 	int (*lock)(struct firedtv *fdtv, u64 addr, __be32 data[]);
-	int (*read)(struct firedtv *fdtv, u64 addr, void *data, size_t len);
+	int (*read)(struct firedtv *fdtv, u64 addr, void *data);
 	int (*write)(struct firedtv *fdtv, u64 addr, void *data, size_t len);
 	int (*start_iso)(struct firedtv *fdtv);
 	void (*stop_iso)(struct firedtv *fdtv);