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-rw-r--r--drivers/w1/slaves/w1_ds2413.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/w1/slaves/w1_ds2413.c b/drivers/w1/slaves/w1_ds2413.c
index d63778c70568..21f08ac8a4e0 100644
--- a/drivers/w1/slaves/w1_ds2413.c
+++ b/drivers/w1/slaves/w1_ds2413.c
@@ -24,6 +24,7 @@
#define W1_F3A_FUNC_PIO_ACCESS_READ 0xF5
#define W1_F3A_FUNC_PIO_ACCESS_WRITE 0x5A
#define W1_F3A_SUCCESS_CONFIRM_BYTE 0xAA
+#define W1_F3A_INVALID_PIO_STATE 0xFF
static ssize_t state_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf, loff_t off,
@@ -45,6 +46,7 @@ static ssize_t state_read(struct file *filp, struct kobject *kobj,
mutex_lock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "mutex locked");
+next:
if (w1_reset_select_slave(sl))
goto out;
@@ -52,10 +54,15 @@ static ssize_t state_read(struct file *filp, struct kobject *kobj,
w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
*buf = w1_read_8(sl->master);
- /* check for correct complement */
if ((*buf & 0x0F) == ((~*buf >> 4) & 0x0F)) {
+ /* complement is correct */
bytes_read = 1;
goto out;
+ } else if (*buf == 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);
+ goto next;
}
if (w1_reset_resume_command(sl->master))