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-rw-r--r--drivers/i2c/busses/i2c-au1550.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-au1550.c b/drivers/i2c/busses/i2c-au1550.c
index 2f684166c43..7d51a43b38d 100644
--- a/drivers/i2c/busses/i2c-au1550.c
+++ b/drivers/i2c/busses/i2c-au1550.c
@@ -105,7 +105,7 @@ wait_master_done(struct i2c_au1550_data *adap)
}
static int
-do_address(struct i2c_au1550_data *adap, unsigned int addr, int rd)
+do_address(struct i2c_au1550_data *adap, unsigned int addr, int rd, int q)
{
volatile psc_smb_t *sp;
u32 stat;
@@ -134,6 +134,10 @@ do_address(struct i2c_au1550_data *adap, unsigned int addr, int rd)
if (rd)
addr |= 1;
+ /* zero-byte xfers stop immediately */
+ if (q)
+ addr |= PSC_SMBTXRX_STP;
+
/* Put byte into fifo, start up master.
*/
sp->psc_smbtxrx = addr;
@@ -142,7 +146,7 @@ do_address(struct i2c_au1550_data *adap, unsigned int addr, int rd)
au_sync();
if (wait_ack(adap))
return -EIO;
- return 0;
+ return (q) ? wait_master_done(adap) : 0;
}
static u32
@@ -262,7 +266,8 @@ au1550_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
for (i = 0; !err && i < num; i++) {
p = &msgs[i];
- err = do_address(adap, p->addr, p->flags & I2C_M_RD);
+ err = do_address(adap, p->addr, p->flags & I2C_M_RD,
+ (p->len == 0));
if (err || !p->len)
continue;
if (p->flags & I2C_M_RD)