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-rw-r--r--drivers/w1/slaves/w1_ds2413.c37
1 files changed, 24 insertions, 13 deletions
diff --git a/drivers/w1/slaves/w1_ds2413.c b/drivers/w1/slaves/w1_ds2413.c
index cd3763df69ac..d63778c70568 100644
--- a/drivers/w1/slaves/w1_ds2413.c
+++ b/drivers/w1/slaves/w1_ds2413.c
@@ -30,6 +30,9 @@ static ssize_t state_read(struct file *filp, struct kobject *kobj,
size_t count)
{
struct w1_slave *sl = kobj_to_w1_slave(kobj);
+ unsigned int retries = W1_F3A_RETRIES;
+ ssize_t bytes_read = -EIO;
+
dev_dbg(&sl->dev,
"Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
@@ -42,22 +45,30 @@ static ssize_t state_read(struct file *filp, struct kobject *kobj,
mutex_lock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "mutex locked");
- if (w1_reset_select_slave(sl)) {
- mutex_unlock(&sl->master->bus_mutex);
- return -EIO;
- }
+ if (w1_reset_select_slave(sl))
+ goto out;
- w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
- *buf = w1_read_8(sl->master);
+ while (retries--) {
+ w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
- mutex_unlock(&sl->master->bus_mutex);
- dev_dbg(&sl->dev, "mutex unlocked");
+ *buf = w1_read_8(sl->master);
+ /* check for correct complement */
+ if ((*buf & 0x0F) == ((~*buf >> 4) & 0x0F)) {
+ bytes_read = 1;
+ goto out;
+ }
- /* check for correct complement */
- if ((*buf & 0x0F) != ((~*buf >> 4) & 0x0F))
- return -EIO;
- else
- return 1;
+ if (w1_reset_resume_command(sl->master))
+ goto out; /* unrecoverable error */
+
+ dev_warn(&sl->dev, "PIO_ACCESS_READ error, retries left: %d\n", retries);
+ }
+
+out:
+ mutex_unlock(&sl->master->bus_mutex);
+ dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n",
+ (bytes_read > 0) ? "succeeded" : "error", retries);
+ return bytes_read;
}
static BIN_ATTR_RO(state, 1);