Re: [U-Boot] [PATCH 1/2] i2c: at91_i2c: Wait for TXRDY after sending the first byte

[Yang, Wenyou]

On 2017/11/29 11:25, Alan Ott wrote:

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 <a...@softiron.com>
---

Acked-by:  Wenyou Yang <wenyou.y...@microchip.com>

Thank you for your patch.

  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], &reg->thr);
+               ret = at91_wait_for_xfer(bus, TWI_SR_TXRDY);
+
                for (i = 1; !ret && (i < msg->len); i++) {
                        writel(msg->buf[i], &reg->thr);
                        ret = at91_wait_for_xfer(bus, TWI_SR_TXRDY);

Best Regards,
Wenyou Yang
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