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Commit 2709781b authored by Ben Dooks's avatar Ben Dooks
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I2C: S3C2410: Check ACK on byte transmission 



We should check for the reception of an ACK after transmitting each
data byte. The address send has been correctly checking this, but the
data write byte state should have also been checking for these failures.

As part of the same fix, we remove the ACK checking from the receive
path where it should not have been checking for an ACK which our hardware
was sending.

Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
parent e1441b9a

drivers/i2c/busses/i2c-s3c2410.c

+10 −11
Original line number Diff line number Diff line
@@ -323,7 +323,17 @@ static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) 
		 * end of the message, and if so, work out what to do

		 */



		if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) {

			if (iicstat & S3C2410_IICSTAT_LASTBIT) {

				dev_dbg(i2c->dev, "WRITE: No Ack\n");



				s3c24xx_i2c_stop(i2c, -ECONNREFUSED);

				goto out_ack;

			}

		}



	retry_write:



		if (!is_msgend(i2c)) {

			byte = i2c->msg->buf[i2c->msg_ptr++];

			writeb(byte, i2c->regs + S3C2410_IICDS);
@@ -377,17 +387,6 @@ static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) 
		 * going to do any more read/write

		 */



		if (!(i2c->msg->flags & I2C_M_IGNORE_NAK) &&

		    !(is_msglast(i2c) && is_lastmsg(i2c))) {



			if (iicstat & S3C2410_IICSTAT_LASTBIT) {

				dev_dbg(i2c->dev, "READ: No Ack\n");



				s3c24xx_i2c_stop(i2c, -ECONNREFUSED);

				goto out_ack;

			}

		}



		byte = readb(i2c->regs + S3C2410_IICDS);

		i2c->msg->buf[i2c->msg_ptr++] = byte;