I found only 15 uses of I2C_MSG_OP, out of 653 uses of one of the three macros. Since I2C_MSG_OP has the complete set of flags, I think it should be OK? One of the uses, in drivers/media/i2c/adv7604.c, is as follows: struct i2c_msg msg[2] = { { client->addr, 0, 1, msgbuf0 }, { client->addr, 0 | I2C_M_RD, len, msgbuf1 } I'm not sure what was intended, but I guess the second structure is supposed to only do a read? julia -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html