brcm2708: update to latest patches from RPi Foundation

[openwrt/staging/chunkeey.git] / target / linux / brcm2708 / patches-4.19 / 950-0591-w1-ds2413-add-retry-support-to-state_read.patch

diff --git a/target/linux/brcm2708/patches-4.19/950-0591-w1-ds2413-add-retry-support-to-state_read.patch b/target/linux/brcm2708/patches-4.19/950-0591-w1-ds2413-add-retry-support-to-state_read.patch
new file mode 100644 (file)
index 0000000..07c6157
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.19/950-0591-w1-ds2413-add-retry-support-to-state_read.patch
@@ -0,0 +1,74 @@
+From 91e443597cdd8f89d2b68ea5bf0f0823d1853ab7 Mon Sep 17 00:00:00 2001
+From: Mariusz Bialonczyk <manio@skyboo.net>
+Date: Mon, 20 May 2019 09:05:56 +0200
+Subject: [PATCH] w1: ds2413: add retry support to state_read()
+
+commit c50d09a86172073f55ebac0b92ad5a75907d64e7 upstream.
+
+The state_read() was calling PIO_ACCESS_READ once and bail out if it
+failed for this first time.
+This commit is improving this to trying more times before it give up,
+similarly as the write call is currently doing.
+
+Signed-off-by: Mariusz Bialonczyk <manio@skyboo.net>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/w1/slaves/w1_ds2413.c | 37 +++++++++++++++++++++++------------
+ 1 file changed, 24 insertions(+), 13 deletions(-)
+
+--- 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 *f
+                         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 *f
+       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;
++              }
++
++              if (w1_reset_resume_command(sl->master))
++                      goto out; /* unrecoverable error */
+ 
+-      /* check for correct complement */
+-      if ((*buf & 0x0F) != ((~*buf >> 4) & 0x0F))
+-              return -EIO;
+-      else
+-              return 1;
++              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);