diff options
| -rw-r--r-- | drivers/w1/slaves/w1_ds2413.c | 37 |
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); |