target/linux/bcm27xx/patches-4.19/950-0588-w1-ds2413-output_write-cosmetic-fixes-simplify.patch

   1 From 3280ce5f5483a351f49e84b48ad98df87989346a Mon Sep 17 00:00:00 2001
   2 From: Mariusz Bialonczyk <manio@skyboo.net>
   3 Date: Mon, 20 May 2019 09:05:55 +0200
   4 Subject: [PATCH] w1: ds2413: output_write() cosmetic fixes / simplify
   5
   6 commit ae2ee27aa985232f66421d7cd1c7f4b87c7dba7d upstream.
   7
   8 Make the output_write simpler.
   9 Based on Jean-Francois Dagenais code from:
  10 49695ac46861 ("w1: ds2408: reset on output_write retry with readback")
  11
  12 Signed-off-by: Mariusz Bialonczyk <manio@skyboo.net>
  13 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  14 ---
  15  drivers/w1/slaves/w1_ds2413.c | 19 +++++++++++--------
  16  1 file changed, 11 insertions(+), 8 deletions(-)
  17
  18 --- a/drivers/w1/slaves/w1_ds2413.c
  19 +++ b/drivers/w1/slaves/w1_ds2413.c
  20 @@ -69,6 +69,7 @@ static ssize_t output_write(struct file
  21         struct w1_slave *sl = kobj_to_w1_slave(kobj);
  22         u8 w1_buf[3];
  23         unsigned int retries = W1_F3A_RETRIES;
  24 +       ssize_t bytes_written = -EIO;
  25
  26         if (count != 1 || off != 0)
  27                 return -EFAULT;
  28 @@ -78,7 +79,7 @@ static ssize_t output_write(struct file
  29         dev_dbg(&sl->dev, "mutex locked");
  30
  31         if (w1_reset_select_slave(sl))
  32 -               goto error;
  33 +               goto out;
  34
  35         /* according to the DS2413 datasheet the most significant 6 bits
  36            should be set to "1"s, so do it now */
  37 @@ -91,18 +92,20 @@ static ssize_t output_write(struct file
  38                 w1_write_block(sl->master, w1_buf, 3);
  39
  40                 if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
  41 -                       mutex_unlock(&sl->master->bus_mutex);
  42 -                       dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries);
  43 -                       return 1;
  44 +                       bytes_written = 1;
  45 +                       goto out;
  46                 }
  47                 if (w1_reset_resume_command(sl->master))
  48 -                       goto error;
  49 +                       goto out; /* unrecoverable error */
  50 +
  51 +               dev_warn(&sl->dev, "PIO_ACCESS_WRITE error, retries left: %d\n", retries);
  52         }
  53
  54 -error:
  55 +out:
  56         mutex_unlock(&sl->master->bus_mutex);
  57 -       dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
  58 -       return -EIO;
  59 +       dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n",
  60 +               (bytes_written > 0) ? "succeeded" : "error", retries);
  61 +       return bytes_written;
  62  }
  63
  64  static BIN_ATTR(output, S_IRUGO | S_IWUSR | S_IWGRP, NULL, output_write, 1);