Commit 349ced99 authored Apr 24, 2019 by Andrey Smirnov Committed by Sebastian Reichel Apr 26, 2019

power: supply: sysfs: prevent endless uevent loop with CONFIG_POWER_SUPPLY_DEBUG

Fix a similar endless event loop as was done in commit
8dcf3217 ("i2c: prevent endless uevent loop with
CONFIG_I2C_DEBUG_CORE"):

  The culprit is the dev_dbg printk in the i2c uevent handler. If
  this is activated (for instance by CONFIG_I2C_DEBUG_CORE) it results
  in an endless loop with systemd-journald.

  This happens if user-space scans the system log and reads the uevent
  file to get information about a newly created device, which seems
  fair use to me. Unfortunately reading the "uevent" file uses the
  same function that runs for creating the uevent for a new device,
  generating the next syslog entry

Both CONFIG_I2C_DEBUG_CORE and CONFIG_POWER_SUPPLY_DEBUG were reported
in https://bugs.freedesktop.org/show_bug.cgi?id=76886

 but only former
seems to have been fixed. Drop debug prints as it was done in I2C
subsystem to resolve the issue.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Chris Healy <cphealy@gmail.com>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

parent dbe7208c

drivers/power/supply/power_supply_sysfs.c

+0 −6

Original line number	Original line	Diff line number	Diff line
	@@ -383,15 +383,11 @@ int power_supply_uevent(struct device dev, struct kobj_uevent_env env)
	char *prop_buf;		char *prop_buf;
	char *attrname;		char *attrname;

	dev_dbg(dev, "uevent\n");

	if (!psy \|\| !psy->desc) {		if (!psy \|\| !psy->desc) {
	dev_dbg(dev, "No power supply yet\n");		dev_dbg(dev, "No power supply yet\n");
	return ret;		return ret;
	}		}

	dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->desc->name);

	ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->desc->name);		ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->desc->name);
	if (ret)		if (ret)
	return ret;		return ret;
	@@ -427,8 +423,6 @@ int power_supply_uevent(struct device dev, struct kobj_uevent_env env)
	goto out;		goto out;
	}		}

	dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);

	ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);		ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
	kfree(attrname);		kfree(attrname);
	if (ret)		if (ret)