Commit 67a97845 authored Sep 04, 2014 by Jiri Kosina

HID: thingm: fix workqueue race on remove

thingm_remove_rgb() needs to flush the workqueue after all the LED classes
have been unregistered, otherwise the removal might race with another LED
event coming, causing thingm_led_set() to schedule additional work after
thingm_remove_rgb() has flushed it. This obviously causes oops later, as
the scheduled work has been freed in the meantime.

In addition to that, move the hid_hw_stop() to an earlier place, so that
dmesg is not polluted by failure messages about not being able to write
the LED while the device is being shut down.

Reported-and-tested-by: Dylan Alex Simon <dylan-kernel@dylex.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

parent 8f507ef5

drivers/hid/hid-thingm.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -208,10 +208,10 @@ unregister_red:

		static void thingm_remove_rgb(struct thingm_rgb *rgb)
		{
		flush_work(&rgb->work);
		led_classdev_unregister(&rgb->red.ldev);
		led_classdev_unregister(&rgb->green.ldev);
		led_classdev_unregister(&rgb->blue.ldev);
		flush_work(&rgb->work);
		}

		static int thingm_probe(struct hid_device hdev, const struct hid_device_id id)
		@@ -286,10 +286,10 @@ static void thingm_remove(struct hid_device *hdev)
		struct thingm_device *tdev = hid_get_drvdata(hdev);
		int i;

		hid_hw_stop(hdev);

		for (i = 0; i < tdev->fwinfo->numrgb; ++i)
		thingm_remove_rgb(tdev->rgb + i);

		hid_hw_stop(hdev);
		}

		static const struct hid_device_id thingm_table[] = {

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