When the au1550 i2c driver addresses a nonexistant slave or does smbus
quick detection it returns to the upper layers without sending a proper
i2c stop condition. This resulted in the minute register of the RTC on
my board to be overwritten with a random value on a following transfer.
Fix the driver to send a stop over the i2c bus after receiving a NACK and
probing for slaves.
Signed-off-by: Manuel Lauss <mano@xxxxxxxxxxxxxxxxxxxxxxx>
--- a/drivers/i2c/busses/i2c-au1550.c 2007-04-26 05:08:32.000000000 +0200
+++ b/drivers/i2c/busses/i2c-au1550.c 2007-05-15 18:49:30.000000000 +0200
@@ -260,14 +260,18 @@ static int
au1550_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
{
struct i2c_au1550_data *adap = i2c_adap->algo_data;
+ volatile psc_smb_t *sp = (volatile psc_smb_t *)(adap->psc_base);
struct i2c_msg *p;
int i, err = 0;
for (i = 0; !err && i < num; i++) {
p = &msgs[i];
err = do_address(adap, p->addr, p->flags & I2C_M_RD);
- if (err || !p->len)
+ if (err || !p->len) {
+ sp->psc_smbtxrx = PSC_SMBTXRX_STP;
+ wait_master_done(adap);
continue;
+ }
if (p->flags & I2C_M_RD)
err = i2c_read(adap, p->buf, p->len);
else
