Commit 9590e9aa authored by Mariusz Bialonczyk's avatar Mariusz Bialonczyk Committed by Phil Elwell
Browse files

w1: ds2413: fix state byte comparision 



commit aacd152e upstream.

This commit is fixing a smatch warning:
drivers/w1/slaves/w1_ds2413.c:61 state_read() warn: impossible condition '(*buf == 255) => ((-128)-127 == 255)'
by creating additional u8 variable for the bus reading and comparision

Reported-by: default avatarkbuild test robot <lkp@intel.com>
Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 3856032a ("w1: ds2413: when the slave is not responding during read, select it again")
Signed-off-by: default avatarMariusz Bialonczyk <manio@skyboo.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent eb7c93f1

drivers/w1/slaves/w1_ds2413.c

+5 −3
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ static ssize_t state_read(struct file *filp, struct kobject *kobj, 
	struct w1_slave *sl = kobj_to_w1_slave(kobj);

	unsigned int retries = W1_F3A_RETRIES;

	ssize_t bytes_read = -EIO;

	u8 state;



	dev_dbg(&sl->dev,

		"Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
@@ -53,12 +54,13 @@ next: 
	while (retries--) {

		w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);



		*buf = w1_read_8(sl->master);

		if ((*buf & 0x0F) == ((~*buf >> 4) & 0x0F)) {

		state = w1_read_8(sl->master);

		if ((state & 0x0F) == ((~state >> 4) & 0x0F)) {

			/* complement is correct */

			*buf = state;

			bytes_read = 1;

			goto out;

		} else if (*buf == W1_F3A_INVALID_PIO_STATE) {

		} else if (state == W1_F3A_INVALID_PIO_STATE) {

			/* slave didn't respond, try to select it again */

			dev_warn(&sl->dev, "slave device did not respond to PIO_ACCESS_READ, " \

					    "reselecting, retries left: %d\n", retries);