From 69c843b45eb3b8f267019e6a05860c9c48337419 Mon Sep 17 00:00:00 2001 From: Alan Stern <stern@rowland.harvard.edu> Date: Wed, 6 Jul 2011 10:52:23 +0200 Subject: [PATCH] PM / Runtime: Prevent runtime_resume from racing with probe 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> --- drivers/base/power/sysfs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c index a9f5b8979611..942d6a7c9ae1 100644 --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -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; } -- GitLab