commit 59596e56da345d7e52b69f744be2d0105a3bb271
author Alan Ott <alan@softiron.com> Tue Nov 28 22:25:23 2017 -0500
committer Heiko Schocher <hs@denx.de> Thu Dec 07 09:28:58 2017 +0100
tree de853ec28e771d202d429b69049ca38c6d5e2d2e
parent 9ba506d13fd253c5a5186f63d79fef6489cf401e

i2c: at91_i2c: Wait for TXRDY after sending the first byte

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>
Reviewed-by: Heiko Schocher <hs@denx.de>

drivers/i2c/at91_i2c.c

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 @@
 
 	} 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);