target/linux/generic/backport-6.6/803-v6.5-05-leds-trigger-netdev-Use-mutex-instead-of-spinlocks.patch

   1 From d1b9e1391ab2dc80e9db87fe8b2de015c651e4c9 Mon Sep 17 00:00:00 2001
   2 From: Christian Marangi <ansuelsmth@gmail.com>
   3 Date: Wed, 19 Apr 2023 23:07:43 +0200
   4 Subject: [PATCH 5/5] leds: trigger: netdev: Use mutex instead of spinlocks
   5
   6 Some LEDs may require to sleep while doing some operation like setting
   7 brightness and other cleanup.
   8
   9 For this reason, using a spinlock will cause a sleep under spinlock
  10 warning.
  11
  12 It should be safe to convert this to a sleepable lock since:
  13 - sysfs read/write can sleep
  14 - netdev_trig_work is a work queue and can sleep
  15 - netdev _trig_notify can sleep
  16
  17 The spinlock was used when brightness didn't support sleeping, but this
  18 changed and now it supported with brightness_set_blocking().
  19
  20 Convert to mutex lock to permit sleeping using brightness_set_blocking().
  21
  22 Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  23 Reviewed-by: Andrew Lunn <andrew@lunn.ch>
  24 Signed-off-by: Lee Jones <lee@kernel.org>
  25 Link: https://lore.kernel.org/r/20230419210743.3594-6-ansuelsmth@gmail.com
  26 ---
  27  drivers/leds/trigger/ledtrig-netdev.c | 18 +++++++++---------
  28  1 file changed, 9 insertions(+), 9 deletions(-)
  29
  30 --- a/drivers/leds/trigger/ledtrig-netdev.c
  31 +++ b/drivers/leds/trigger/ledtrig-netdev.c
  32 @@ -20,7 +20,7 @@
  33  #include <linux/list.h>
  34  #include <linux/module.h>
  35  #include <linux/netdevice.h>
  36 -#include <linux/spinlock.h>
  37 +#include <linux/mutex.h>
  38  #include <linux/timer.h>
  39  #include "../leds.h"
  40
  41 @@ -37,7 +37,7 @@
  42   */
  43
  44  struct led_netdev_data {
  45 -       spinlock_t lock;
  46 +       struct mutex lock;
  47
  48         struct delayed_work work;
  49         struct notifier_block notifier;
  50 @@ -97,9 +97,9 @@ static ssize_t device_name_show(struct d
  51         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
  52         ssize_t len;
  53
  54 -       spin_lock_bh(&trigger_data->lock);
  55 +       mutex_lock(&trigger_data->lock);
  56         len = sprintf(buf, "%s\n", trigger_data->device_name);
  57 -       spin_unlock_bh(&trigger_data->lock);
  58 +       mutex_unlock(&trigger_data->lock);
  59
  60         return len;
  61  }
  62 @@ -115,7 +115,7 @@ static ssize_t device_name_store(struct
  63
  64         cancel_delayed_work_sync(&trigger_data->work);
  65
  66 -       spin_lock_bh(&trigger_data->lock);
  67 +       mutex_lock(&trigger_data->lock);
  68
  69         if (trigger_data->net_dev) {
  70                 dev_put(trigger_data->net_dev);
  71 @@ -138,7 +138,7 @@ static ssize_t device_name_store(struct
  72         trigger_data->last_activity = 0;
  73
  74         set_baseline_state(trigger_data);
  75 -       spin_unlock_bh(&trigger_data->lock);
  76 +       mutex_unlock(&trigger_data->lock);
  77
  78         return size;
  79  }
  80 @@ -279,7 +279,7 @@ static int netdev_trig_notify(struct not
  81
  82         cancel_delayed_work_sync(&trigger_data->work);
  83
  84 -       spin_lock_bh(&trigger_data->lock);
  85 +       mutex_lock(&trigger_data->lock);
  86
  87         trigger_data->carrier_link_up = false;
  88         switch (evt) {
  89 @@ -304,7 +304,7 @@ static int netdev_trig_notify(struct not
  90
  91         set_baseline_state(trigger_data);
  92
  93 -       spin_unlock_bh(&trigger_data->lock);
  94 +       mutex_unlock(&trigger_data->lock);
  95
  96         return NOTIFY_DONE;
  97  }
  98 @@ -365,7 +365,7 @@ static int netdev_trig_activate(struct l
  99         if (!trigger_data)
 100                 return -ENOMEM;
 101
 102 -       spin_lock_init(&trigger_data->lock);
 103 +       mutex_init(&trigger_data->lock);
 104
 105         trigger_data->notifier.notifier_call = netdev_trig_notify;
 106         trigger_data->notifier.priority = 10;