[PATCH 1/4] w1: ds2413: output_write() cosmetic fixes / simplify

From: Mariusz Bialonczyk
Date: Mon May 20 2019 - 03:08:31 EST


Make the output_write simpler.
Based on Jean-Francois Dagenais code from:
49695ac46861 ("w1: ds2408: reset on output_write retry with readback")

Signed-off-by: Mariusz Bialonczyk <manio@xxxxxxxxxx>
---
drivers/w1/slaves/w1_ds2413.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/w1/slaves/w1_ds2413.c b/drivers/w1/slaves/w1_ds2413.c
index 492e3d010321..cd3763df69ac 100644
--- a/drivers/w1/slaves/w1_ds2413.c
+++ b/drivers/w1/slaves/w1_ds2413.c
@@ -69,6 +69,7 @@ static ssize_t output_write(struct file *filp, struct kobject *kobj,
struct w1_slave *sl = kobj_to_w1_slave(kobj);
u8 w1_buf[3];
unsigned int retries = W1_F3A_RETRIES;
+ ssize_t bytes_written = -EIO;

if (count != 1 || off != 0)
return -EFAULT;
@@ -78,7 +79,7 @@ static ssize_t output_write(struct file *filp, struct kobject *kobj,
dev_dbg(&sl->dev, "mutex locked");

if (w1_reset_select_slave(sl))
- goto error;
+ goto out;

/* according to the DS2413 datasheet the most significant 6 bits
should be set to "1"s, so do it now */
@@ -91,18 +92,20 @@ static ssize_t output_write(struct file *filp, struct kobject *kobj,
w1_write_block(sl->master, w1_buf, 3);

if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
- mutex_unlock(&sl->master->bus_mutex);
- dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries);
- return 1;
+ bytes_written = 1;
+ goto out;
}
if (w1_reset_resume_command(sl->master))
- goto error;
+ goto out; /* unrecoverable error */
+
+ dev_warn(&sl->dev, "PIO_ACCESS_WRITE error, retries left: %d\n", retries);
}

-error:
+out:
mutex_unlock(&sl->master->bus_mutex);
- dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
- return -EIO;
+ dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n",
+ (bytes_written > 0) ? "succeeded" : "error", retries);
+ return bytes_written;
}

static BIN_ATTR(output, S_IRUGO | S_IWUSR | S_IWGRP, NULL, output_write, 1);
--
2.19.0.rc1