i2c: rk3x: fix 0 length write transfers

i2cdetect -q was broken (everything was a false positive, and no transfers were
actually being sent over i2c). The way it works is by sending a 0 length write
request and checking for NACK. This patch fixes the 0 length writes and actually
sends them.

Reported-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>
Tested-by: Max Schwarz <max.schwarz@online.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 93cfc83..b38b052 100644 (file)
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -238,7 +238,7 @@ static void rk3x_i2c_fill_transmit_buf(struct rk3x_i2c *i2c)
        for (i = 0; i < 8; ++i) {
                val = 0;
                for (j = 0; j < 4; ++j) {
-                       if (i2c->processed == i2c->msg->len)
+                       if ((i2c->processed == i2c->msg->len) && (cnt != 0))
                                break;
 
                        if (i2c->processed == 0 && cnt == 0)