target/linux/generic/hack-4.19/160-leds-fix-regression-in-usbport-led-trigger.patch

   1 From 38a3549ffc0033761063cc5c7b994ab075694db8 Mon Sep 17 00:00:00 2001
   2 From: Christian Lamparter <chunkeey@gmail.com>
   3 Date: Tue, 25 Dec 2018 21:11:08 +0100
   4 Subject: [RFC PATCH] leds: fix regression in usbport led trigger
   5
   6 In the patch "usb: simplify usbport trigger" together with
   7 "leds: triggers: add device attribute support" caused an
   8 regression for the usbport trigger. it will no longer
   9 enumerate any "ports" (i.e the sysfs directory stays empty)
  10 if the usb host drivers are fully initialized before the
  11 usbport trigger was loaded.
  12
  13 The reason is that the usbport driver registers the sysfs
  14 entries in the ports subdirectory during the activate()
  15 callback. Whereas the patch
  16 "leds: triggers: add device attribute support" made it so
  17 that the sysfs "ports" group was only being added after
  18 the activate() callback succeeded.
  19
  20 This patch moves the device_add_groups() in front of the
  21 call to the trigger's activate() function in order to
  22 solve the problem.
  23
  24 Fixes: 6f7b0bad8839 ("usb: simplify usbport trigger")
  25 Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
  26 ---
  27  drivers/leds/led-triggers.c | 19 ++++++++++---------
  28  1 file changed, 10 insertions(+), 9 deletions(-)
  29
  30 diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
  31 index 17d73db1456e..08e7c724a9dc 100644
  32 --- a/drivers/leds/led-triggers.c
  33 +++ b/drivers/leds/led-triggers.c
  34 @@ -134,6 +134,12 @@ int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
  35                 led_set_brightness(led_cdev, LED_OFF);
  36         }
  37         if (trig) {
  38 +               ret = device_add_groups(led_cdev->dev, trig->groups);
  39 +               if (ret) {
  40 +                       dev_err(led_cdev->dev, "Failed to add trigger attributes\n");
  41 +                       goto err_add_groups;
  42 +               }
  43 +
  44                 write_lock_irqsave(&trig->leddev_list_lock, flags);
  45                 list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
  46                 write_unlock_irqrestore(&trig->leddev_list_lock, flags);
  47 @@ -146,12 +152,6 @@ int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
  48
  49                 if (ret)
  50                         goto err_activate;
  51 -
  52 -               ret = device_add_groups(led_cdev->dev, trig->groups);
  53 -               if (ret) {
  54 -                       dev_err(led_cdev->dev, "Failed to add trigger attributes\n");
  55 -                       goto err_add_groups;
  56 -               }
  57         }
  58
  59         if (event) {
  60 @@ -165,17 +165,18 @@ int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
  61
  62         return 0;
  63
  64 -err_add_groups:
  65 -
  66 +err_activate:
  67 +       device_remove_groups(led_cdev->dev, trig->groups);
  68         if (trig->deactivate)
  69                 trig->deactivate(led_cdev);
  70 -err_activate:
  71
  72         led_cdev->trigger = NULL;
  73         led_cdev->trigger_data = NULL;
  74         write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
  75         list_del(&led_cdev->trig_list);
  76         write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
  77 +
  78 +err_add_groups:
  79         led_set_brightness(led_cdev, LED_OFF);
  80
  81         return ret;
  82 --
  83 2.20.1
  84