Biggest problem of that function is complexity. Try reduce complexity:
* define macros to detect all 3 supported xfers
* remove duplicate message maximum size checks
Signed-off-by: Antti Palosaari <crope@xxxxxx>
---
drivers/media/usb/dvb-usb-v2/af9035.c | 37 +++++++++++++----------------------
1 file changed, 14 insertions(+), 23 deletions(-)
diff --git a/drivers/media/usb/dvb-usb-v2/af9035.c b/drivers/media/usb/dvb-usb-v2/af9035.c
index 6534e44..ec62133 100644
--- a/drivers/media/usb/dvb-usb-v2/af9035.c
+++ b/drivers/media/usb/dvb-usb-v2/af9035.c
@@ -319,8 +319,14 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap,
* bus, having same slave address. Due to that we reuse demod address,
* shifted by one bit, on that case.
*/
- if (num == 2 && !(msg[0].flags & I2C_M_RD) &&
- (msg[1].flags & I2C_M_RD)) {
+#define AF9035_IS_I2C_XFER_WRITE_READ(_msg, _num) \
+ (_num == 2 && !(_msg[0].flags & I2C_M_RD) && (_msg[1].flags & I2C_M_RD))
+#define AF9035_IS_I2C_XFER_WRITE(_msg, _num) \
+ (_num == 1 && !(_msg[0].flags & I2C_M_RD))
+#define AF9035_IS_I2C_XFER_READ(_msg, _num) \
+ (_num == 1 && (_msg[0].flags & I2C_M_RD))
+
+ if (AF9035_IS_I2C_XFER_WRITE_READ(msg, num)) {
if (msg[0].len > 40 || msg[1].len > 40) {
/* TODO: correct limits > 40 */
ret = -EOPNOTSUPP;
@@ -338,18 +344,11 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap,
ret = af9035_rd_regs(d, reg, &msg[1].buf[0],
msg[1].len);
} else {
- /* I2C */
+ /* I2C write + read */
u8 buf[MAX_XFER_SIZE];
struct usb_req req = { CMD_I2C_RD, 0, 5 + msg[0].len,
buf, msg[1].len, msg[1].buf };
- if (5 + msg[0].len > sizeof(buf)) {
- dev_warn(&d->udev->dev,
- "%s: i2c xfer: len=%d is too big!\n",
- KBUILD_MODNAME, msg[0].len);
- ret = -EOPNOTSUPP;
- goto unlock;
- }
req.mbox |= ((msg[0].addr & 0x80) >> 3);
buf[0] = msg[1].len;
buf[1] = msg[0].addr << 1;
@@ -359,7 +358,7 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap,
memcpy(&buf[5], msg[0].buf, msg[0].len);
ret = af9035_ctrl_msg(d, &req);
}
- } else if (num == 1 && !(msg[0].flags & I2C_M_RD)) {
+ } else if (AF9035_IS_I2C_XFER_WRITE(msg, num)) {
if (msg[0].len > 40) {
/* TODO: correct limits > 40 */
ret = -EOPNOTSUPP;
@@ -377,18 +376,11 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap,
ret = af9035_wr_regs(d, reg, &msg[0].buf[3],
msg[0].len - 3);
} else {
- /* I2C */
+ /* I2C write */
u8 buf[MAX_XFER_SIZE];
struct usb_req req = { CMD_I2C_WR, 0, 5 + msg[0].len,
buf, 0, NULL };
- if (5 + msg[0].len > sizeof(buf)) {
- dev_warn(&d->udev->dev,
- "%s: i2c xfer: len=%d is too big!\n",
- KBUILD_MODNAME, msg[0].len);
- ret = -EOPNOTSUPP;
- goto unlock;
- }
req.mbox |= ((msg[0].addr & 0x80) >> 3);
buf[0] = msg[0].len;
buf[1] = msg[0].addr << 1;
@@ -398,12 +390,12 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap,
memcpy(&buf[5], msg[0].buf, msg[0].len);
ret = af9035_ctrl_msg(d, &req);
}
- } else if (num == 1 && (msg[0].flags & I2C_M_RD)) {
+ } else if (AF9035_IS_I2C_XFER_READ(msg, num)) {
if (msg[0].len > 40) {
/* TODO: correct limits > 40 */
ret = -EOPNOTSUPP;
} else {
- /* I2C */
+ /* I2C read */
u8 buf[5];
struct usb_req req = { CMD_I2C_RD, 0, sizeof(buf),
buf, msg[0].len, msg[0].buf };
@@ -418,14 +410,13 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap,
} else {
/*
* We support only three kind of I2C transactions:
- * 1) 1 x read + 1 x write (repeated start)
+ * 1) 1 x write + 1 x read (repeated start)
* 2) 1 x write
* 3) 1 x read
*/
ret = -EOPNOTSUPP;
}
-unlock:
mutex_unlock(&d->i2c_mutex);
if (ret < 0)
--
http://palosaari.fi/
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