The driver must wait for TXRDY after each byte is pushed into the i2c FIFO before pushing the next byte. Previously this was not done for the first byte, causing a race condition with zeros sometimes being sent for the next byte (which is typically the first actual data byte).
Signed-off-by: Alan Ott alan@softiron.com --- drivers/i2c/at91_i2c.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/i2c/at91_i2c.c b/drivers/i2c/at91_i2c.c index d394044..20d0929 100644 --- a/drivers/i2c/at91_i2c.c +++ b/drivers/i2c/at91_i2c.c @@ -72,6 +72,8 @@ static int at91_i2c_xfer_msg(struct at91_i2c_bus *bus, struct i2c_msg *msg)
} else { writel(msg->buf[0], ®->thr); + ret = at91_wait_for_xfer(bus, TWI_SR_TXRDY); + for (i = 1; !ret && (i < msg->len); i++) { writel(msg->buf[i], ®->thr); ret = at91_wait_for_xfer(bus, TWI_SR_TXRDY);