patch "USB: leds: fix regression in usbport led trigger" added to usb-linus

patch "USB: leds: fix regression in usbport led trigger" added to usb-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

    USB: leds: fix regression in usbport led trigger

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


From 91f7d2e89868fcac0e750a28230fdb1ad4512137 Mon Sep 17 00:00:00 2001
From: Christian Lamparter <chunkeey@gmail.com>
Date: Fri, 11 Jan 2019 17:29:45 +0100
Subject: USB: leds: fix regression in usbport led trigger

The patch "usb: simplify usbport trigger" together with "leds: triggers:
add device attribute support" caused an regression for the usbport
trigger. it will no longer enumerate any active usb hub ports under the
"ports" directory in the sysfs class directory, if the usb host drivers
are fully initialized before the usbport trigger was loaded.

The reason is that the usbport driver tries to register the sysfs
entries during the activate() callback. And this will fail with -2 /
ENOENT because the patch "leds: triggers: add device attribute support"
made it so that the sysfs "ports" group was only being added after the
activate() callback succeeded.

This version of the patch reverts parts of the "usb: simplify usbport
trigger" patch and restores usbport trigger's functionality.

Fixes: 6f7b0bad8839 ("usb: simplify usbport trigger")
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/core/ledtrig-usbport.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/core/ledtrig-usbport.c b/drivers/usb/core/ledtrig-usbport.c
index dc7f7fd71684..c12ac56606c3 100644
--- a/drivers/usb/core/ledtrig-usbport.c
+++ b/drivers/usb/core/ledtrig-usbport.c
@@ -119,11 +119,6 @@ static const struct attribute_group ports_group = {
 	.attrs = ports_attrs,
 };
 
-static const struct attribute_group *ports_groups[] = {
-	&ports_group,
-	NULL
-};
-
 /***************************************
  * Adding & removing ports
  ***************************************/
@@ -307,6 +302,7 @@ static int usbport_trig_notify(struct notifier_block *nb, unsigned long action,
 static int usbport_trig_activate(struct led_classdev *led_cdev)
 {
 	struct usbport_trig_data *usbport_data;
+	int err;
 
 	usbport_data = kzalloc(sizeof(*usbport_data), GFP_KERNEL);
 	if (!usbport_data)
@@ -315,6 +311,9 @@ static int usbport_trig_activate(struct led_classdev *led_cdev)
 
 	/* List of ports */
 	INIT_LIST_HEAD(&usbport_data->ports);
+	err = sysfs_create_group(&led_cdev->dev->kobj, &ports_group);
+	if (err)
+		goto err_free;
 	usb_for_each_dev(usbport_data, usbport_trig_add_usb_dev_ports);
 	usbport_trig_update_count(usbport_data);
 
@@ -322,8 +321,11 @@ static int usbport_trig_activate(struct led_classdev *led_cdev)
 	usbport_data->nb.notifier_call = usbport_trig_notify;
 	led_set_trigger_data(led_cdev, usbport_data);
 	usb_register_notify(&usbport_data->nb);
-
 	return 0;
+
+err_free:
+	kfree(usbport_data);
+	return err;
 }
 
 static void usbport_trig_deactivate(struct led_classdev *led_cdev)
@@ -335,6 +337,8 @@ static void usbport_trig_deactivate(struct led_classdev *led_cdev)
 		usbport_trig_remove_port(usbport_data, port);
 	}
 
+	sysfs_remove_group(&led_cdev->dev->kobj, &ports_group);
+
 	usb_unregister_notify(&usbport_data->nb);
 
 	kfree(usbport_data);
@@ -344,7 +348,6 @@ static struct led_trigger usbport_led_trigger = {
 	.name     = "usbport",
 	.activate = usbport_trig_activate,
 	.deactivate = usbport_trig_deactivate,
-	.groups = ports_groups,
 };
 
 static int __init usbport_trig_init(void)
-- 
2.20.1