queue-4.4/power-supply-sysfs-prevent-endless-uevent-loop-with-.patch

   1 From c3def3c3d3fee8e0d35154554f83635a97542085 Mon Sep 17 00:00:00 2001
   2 From: Andrey Smirnov <andrew.smirnov@gmail.com>
   3 Date: Wed, 24 Apr 2019 00:16:10 -0700
   4 Subject: power: supply: sysfs: prevent endless uevent loop with
   5  CONFIG_POWER_SUPPLY_DEBUG
   6
   7 [ Upstream commit 349ced9984ff540ce74ca8a0b2e9b03dc434b9dd ]
   8
   9 Fix a similar endless event loop as was done in commit
  10 8dcf32175b4e ("i2c: prevent endless uevent loop with
  11 CONFIG_I2C_DEBUG_CORE"):
  12
  13   The culprit is the dev_dbg printk in the i2c uevent handler. If
  14   this is activated (for instance by CONFIG_I2C_DEBUG_CORE) it results
  15   in an endless loop with systemd-journald.
  16
  17   This happens if user-space scans the system log and reads the uevent
  18   file to get information about a newly created device, which seems
  19   fair use to me. Unfortunately reading the "uevent" file uses the
  20   same function that runs for creating the uevent for a new device,
  21   generating the next syslog entry
  22
  23 Both CONFIG_I2C_DEBUG_CORE and CONFIG_POWER_SUPPLY_DEBUG were reported
  24 in https://bugs.freedesktop.org/show_bug.cgi?id=76886 but only former
  25 seems to have been fixed. Drop debug prints as it was done in I2C
  26 subsystem to resolve the issue.
  27
  28 Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
  29 Cc: Chris Healy <cphealy@gmail.com>
  30 Cc: linux-pm@vger.kernel.org
  31 Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
  32 Signed-off-by: Sasha Levin <sashal@kernel.org>
  33 ---
  34  drivers/power/power_supply_sysfs.c | 6 ------
  35  1 file changed, 6 deletions(-)
  36
  37 diff --git a/drivers/power/power_supply_sysfs.c b/drivers/power/power_supply_sysfs.c
  38 index ed2d7fd0c734d..488dd7eb0aeb7 100644
  39 --- a/drivers/power/power_supply_sysfs.c
  40 +++ b/drivers/power/power_supply_sysfs.c
  41 @@ -277,15 +277,11 @@ int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
  42         char *prop_buf;
  43         char *attrname;
  44
  45 -       dev_dbg(dev, "uevent\n");
  46 -
  47         if (!psy || !psy->desc) {
  48                 dev_dbg(dev, "No power supply yet\n");
  49                 return ret;
  50         }
  51
  52 -       dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->desc->name);
  53 -
  54         ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->desc->name);
  55         if (ret)
  56                 return ret;
  57 @@ -321,8 +317,6 @@ int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
  58                         goto out;
  59                 }
  60
  61 -               dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
  62 -
  63                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
  64                 kfree(attrname);
  65                 if (ret)
  66 --
  67 2.20.1
  68