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: Marcus Folkesson <marcus.folkesson@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Marcus Folkesson 2018-03-17 10:52:39 -07:00 committed by Dmitry Torokhov
parent 553d16af23
commit 12e510dbc5

View File

@ -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;
}