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PM / Runtime: Prevent runtime_resume from racing with probe

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This patch (as1475) adds device_lock() and device_unlock() calls to
the store methods for the power/control and power/autosuspend_delay_ms
sysfs attribute files.  We don't want badly timed writes to these
files to cause runtime_resume callbacks to occur while a driver is
being probed for a device.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This commit is contained in:
Alan Stern 2011-07-06 10:52:23 +02:00 committed by Rafael J. Wysocki
parent 62052ab1d1
commit 69c843b45e
1 changed files with 5 additions and 1 deletions
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6
drivers/base/power/sysfs.c
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@ -116,12 +116,14 @@ static ssize_t control_store(struct device * dev, struct device_attribute *attr,
cp = memchr(buf, '\n', n);
if (cp)
len = cp - buf;
device_lock(dev);
if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0)
pm_runtime_allow(dev);
else if (len == sizeof ctrl_on - 1 && strncmp(buf, ctrl_on, len) == 0)
pm_runtime_forbid(dev);
else
return -EINVAL;
n = -EINVAL;
device_unlock(dev);
return n;
}
@ -205,7 +207,9 @@ static ssize_t autosuspend_delay_ms_store(struct device *dev,
if (strict_strtol(buf, 10, &delay) != 0 || delay != (int) delay)
return -EINVAL;
device_lock(dev);
pm_runtime_set_autosuspend_delay(dev, delay);
device_unlock(dev);
return n;
}