From: Jonathan Cameron Date: Sun, 24 Mar 2013 16:58:00 +0000 (+0000) Subject: staging:iio:magnetometer:ak8975 drop I2C_M_NOSTART flag in read_data X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=aa9922579fee20ac4f2bb959a79bbfbff2c04585;p=openwrt%2Fstaging%2Fblogic.git staging:iio:magnetometer:ak8975 drop I2C_M_NOSTART flag in read_data This flag makes no sense whatsoever where it is. Documentation/i2c/i2c-protocol states: If you set the I2C_M_NOSTART variable for the first partial message, we do not generate Addr, but we do generate the startbit S. This will probably confuse all other clients on your bus, so don't try this. This is exactly what is going on here. Likelihood given that the driver never checked for this protocol mangling being available is that it wasn't present on the test boards and hence this flag was simply ignored. No indication of why it would be necessary has been found in the datasheets. Signed-off-by: Jonathan Cameron Acked-by: Laxman Dewangan --- diff --git a/drivers/staging/iio/magnetometer/ak8975.c b/drivers/staging/iio/magnetometer/ak8975.c index 8726ea1de083..1428849fd5a2 100644 --- a/drivers/staging/iio/magnetometer/ak8975.c +++ b/drivers/staging/iio/magnetometer/ak8975.c @@ -132,7 +132,6 @@ static int ak8975_read_data(struct i2c_client *client, struct i2c_msg msg[2] = { { .addr = client->addr, - .flags = I2C_M_NOSTART, .len = 1, .buf = ®, }, {