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Commit 12e510db authored by Marcus Folkesson's avatar Marcus Folkesson Committed by Dmitry Torokhov
Browse files

Input: usbtouchscreen - fix deadlock in autosuspend 



usb_autopm_get_interface() that is called in usbtouch_open() does an
autoresume if the device is suspended.

input_dev->mutex used in usbtouch_resume() is in this case already
taken by the input subsystem and will cause a deadlock.

Signed-off-by: default avatarMarcus Folkesson <marcus.folkesson@gmail.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 553d16af

drivers/input/touchscreen/usbtouchscreen.c

+11 −4
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ 
#include <linux/usb.h>

#include <linux/usb/input.h>

#include <linux/hid.h>

#include <linux/mutex.h>



static bool swap_xy;

module_param(swap_xy, bool, 0644);
@@ -107,6 +108,7 @@ struct usbtouch_usb { 
	struct usb_interface *interface;

	struct input_dev *input;

	struct usbtouch_device_info *type;

	struct mutex pm_mutex;  /* serialize access to open/suspend */

	char name[128];

	char phys[64];

	void *priv;
@@ -1450,6 +1452,7 @@ static int usbtouch_open(struct input_dev *input) 
	if (r < 0)

		goto out;



	mutex_lock(&usbtouch->pm_mutex);

	if (!usbtouch->type->irq_always) {

		if (usb_submit_urb(usbtouch->irq, GFP_KERNEL)) {

			r = -EIO;
@@ -1459,6 +1462,7 @@ static int usbtouch_open(struct input_dev *input) 


	usbtouch->interface->needs_remote_wakeup = 1;

out_put:

	mutex_unlock(&usbtouch->pm_mutex);

	usb_autopm_put_interface(usbtouch->interface);

out:

	return r;
@@ -1469,8 +1473,11 @@ static void usbtouch_close(struct input_dev *input) 
	struct usbtouch_usb *usbtouch = input_get_drvdata(input);

	int r;



	mutex_lock(&usbtouch->pm_mutex);

	if (!usbtouch->type->irq_always)

		usb_kill_urb(usbtouch->irq);

	mutex_unlock(&usbtouch->pm_mutex);



	r = usb_autopm_get_interface(usbtouch->interface);

	usbtouch->interface->needs_remote_wakeup = 0;

	if (!r)
@@ -1493,10 +1500,10 @@ static int usbtouch_resume(struct usb_interface *intf) 
	struct input_dev *input = usbtouch->input;

	int result = 0;



	mutex_lock(&input->mutex);

	mutex_lock(&usbtouch->pm_mutex);

	if (input->users || usbtouch->type->irq_always)

		result = usb_submit_urb(usbtouch->irq, GFP_NOIO);

	mutex_unlock(&input->mutex);

	mutex_unlock(&usbtouch->pm_mutex);



	return result;

}
@@ -1519,10 +1526,10 @@ static int usbtouch_reset_resume(struct usb_interface *intf) 
	}



	/* restart IO if needed */

	mutex_lock(&input->mutex);

	mutex_lock(&usbtouch->pm_mutex);

	if (input->users)

		err = usb_submit_urb(usbtouch->irq, GFP_NOIO);

	mutex_unlock(&input->mutex);

	mutex_unlock(&usbtouch->pm_mutex);



	return err;

}