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| author | David Fries <David@Fries.net> | 2014-01-15 22:29:15 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-07 15:40:17 -0800 |
| commit | a16130569af7e92b0a68a8c96170d84756f91c47 (patch) | |
| tree | 062e723bc478c110d86fde537a69d264d59b2476 /drivers/w1/w1.c | |
| parent | af8c7237b082acefb996878a21a87017059b2c52 (diff) | |
| download | lwn-a16130569af7e92b0a68a8c96170d84756f91c47.tar.gz lwn-a16130569af7e92b0a68a8c96170d84756f91c47.zip | |
w1: increase w1_max_slave_count, allow write access
w1_max_slave_count is only used to abort the search early
or take a fast search (when 1), so there isn't any reason to not allow
it to be updated through sysfs. Memory is not allocated based on
the current value and 10 is a rather low base number, increasing to
64, and printing a message the first time the count is reached and
there were more devices to discover to let the user know why not
all the devices were found.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/w1/w1.c')
| -rw-r--r-- | drivers/w1/w1.c | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index 92766a9f8b4d..34ffdc6da4fb 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -46,7 +46,7 @@ MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol."); static int w1_timeout = 10; -int w1_max_slave_count = 10; +int w1_max_slave_count = 64; int w1_max_slave_ttl = 10; module_param_named(timeout, w1_timeout, int, 0); @@ -316,6 +316,24 @@ static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct devic return count; } +static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + long tmp; + struct w1_master *md = dev_to_w1_master(dev); + + if (kstrtol(buf, 0, &tmp) == -EINVAL || tmp < 1) + return -EINVAL; + + mutex_lock(&md->mutex); + md->max_slave_count = tmp; + /* allow each time the max_slave_count is updated */ + clear_bit(W1_WARN_MAX_COUNT, &md->flags); + mutex_unlock(&md->mutex); + + return count; +} + static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf) { struct w1_master *md = dev_to_w1_master(dev); @@ -518,7 +536,7 @@ static ssize_t w1_master_attribute_store_remove(struct device *dev, static W1_MASTER_ATTR_RO(name, S_IRUGO); static W1_MASTER_ATTR_RO(slaves, S_IRUGO); static W1_MASTER_ATTR_RO(slave_count, S_IRUGO); -static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO); +static W1_MASTER_ATTR_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP); static W1_MASTER_ATTR_RO(attempts, S_IRUGO); static W1_MASTER_ATTR_RO(timeout, S_IRUGO); static W1_MASTER_ATTR_RO(pointer, S_IRUGO); @@ -976,6 +994,14 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb desc_bit = last_zero; cb(dev, rn); } + + if (!last_device && slave_count == dev->max_slave_count && + !test_bit(W1_WARN_MAX_COUNT, &dev->flags)) { + dev_info(&dev->dev, "%s: max_slave_count %d reached, " + "additional sensors ignored\n", __func__, + dev->max_slave_count); + set_bit(W1_WARN_MAX_COUNT, &dev->flags); + } } } |