Commit ad0194e8 authored Mar 01, 2010 by Luotao Fu Committed by Ben Dooks Mar 07, 2010

i2c-pnx: fix setting start/stop condition



The start/stop condtions are set in different places repetedly in the i2c-pnx
driver.  Beside in i2c_pnx_start and i2c_pnx_stop the start/stop bit are also
set during the transfer of a i2c message in the master_xmit/rcv calls. This is
wrong since we can't set the start/stop condition during the transaction of a
single message any way. As a matter of fact, the driver will sometimes set both
the start and the stop bits at one time. This can be easily reproduced by
sending a simple read request like e.g
struct i2c_msg msgs[] = {
{ addr, 0, 1, buf },
{ addr, I2C_M_RD, offset, buf }
};
While processing the first message the i2c_pnx_master_xmit will set both the
start_bit and the stop_bit, which will eventually confuse the slave.

Fixed by remove setting start/stop condition from the transmit routines.

Signed-off-by: Luotao Fu <l.fu@pengutronix.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

parent 96eb7164

drivers/i2c/busses/i2c-pnx.c

+0 −11

Original line number	Diff line number	Diff line
		@@ -172,12 +172,6 @@ static int i2c_pnx_master_xmit(struct i2c_pnx_algo_data *alg_data)
		/* We still have something to talk about... */
		val = *alg_data->mif.buf++;

		if (alg_data->mif.len == 1) {
		val \|= stop_bit;
		if (!alg_data->last)
		val \|= start_bit;
		}

		alg_data->mif.len--;
		iowrite32(val, I2C_REG_TX(alg_data));

		@@ -251,11 +245,6 @@ static int i2c_pnx_master_rcv(struct i2c_pnx_algo_data *alg_data)
		__func__);

		if (alg_data->mif.len == 1) {
		/* Last byte, do not acknowledge next rcv. */
		val \|= stop_bit;
		if (!alg_data->last)
		val \|= start_bit;

		/*
		* Enable interrupt RFDAIE (data in Rx fifo),
		* and disable DRMIE (need data for Tx)