Alex, On Wed, Oct 1, 2014 at 10:40 AM, Alexandru M Stan <amstan@xxxxxxxxxxxx> wrote: > 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@xxxxxxxxxxxx> > Signed-off-by: Alexandru M Stan <amstan@xxxxxxxxxxxx> > --- > drivers/i2c/busses/i2c-rk3x.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c > index b41d979..f486d0e 100644 > --- 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)) This looks good to me. Basically we still need to write the address of the device onto the bus even if there's no data. Reviewed-by: Doug Anderson <dianders@xxxxxxxxxxxx> Tested-by: Doug Anderson <dianders@xxxxxxxxxxxx> -Doug -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html