diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.19/950-0589-w1-ds2413-add-retry-support-to-state_read.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.19/950-0589-w1-ds2413-add-retry-support-to-state_read.patch | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0589-w1-ds2413-add-retry-support-to-state_read.patch b/target/linux/brcm2708/patches-4.19/950-0589-w1-ds2413-add-retry-support-to-state_read.patch new file mode 100644 index 0000000000..07c6157ca5 --- /dev/null +++ b/target/linux/brcm2708/patches-4.19/950-0589-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); |