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Input: pagasus_notetaker - fix deadlock in autosuspend 

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

input_dev->mutex used in pegasus_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 10:51:34 -07:00 committed by Dmitry Torokhov
parent ff0d2cba64
commit 1f701f6d10
1 changed files with 19 additions and 6 deletions
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25
drivers/input/tablet/pegasus_notetaker.c
View File

@ -41,6 +41,7 @@
#include <linux/usb/input.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/mutex.h>
/* USB HID defines */
#define USB_REQ_GET_REPORT 0x01
@ -76,6 +77,10 @@ struct pegasus {
struct usb_device *usbdev;
struct usb_interface *intf;
struct urb *irq;
/* serialize access to open/suspend */
struct mutex pm_mutex;
char name[128];
char phys[64];
struct work_struct init;
@ -216,6 +221,7 @@ static int pegasus_open(struct input_dev *dev)
if (error)
return error;
mutex_lock(&pegasus->pm_mutex);
pegasus->irq->dev = pegasus->usbdev;
if (usb_submit_urb(pegasus->irq, GFP_KERNEL)) {
error = -EIO;
@ -226,12 +232,14 @@ static int pegasus_open(struct input_dev *dev)
if (error)
goto err_kill_urb;
mutex_unlock(&pegasus->pm_mutex);
return 0;
err_kill_urb:
usb_kill_urb(pegasus->irq);
cancel_work_sync(&pegasus->init);
err_autopm_put:
mutex_unlock(&pegasus->pm_mutex);
usb_autopm_put_interface(pegasus->intf);
return error;
}
@ -240,8 +248,11 @@ static void pegasus_close(struct input_dev *dev)
{
struct pegasus *pegasus = input_get_drvdata(dev);
mutex_lock(&pegasus->pm_mutex);
usb_kill_urb(pegasus->irq);
cancel_work_sync(&pegasus->init);
mutex_unlock(&pegasus->pm_mutex);
usb_autopm_put_interface(pegasus->intf);
}
@ -274,6 +285,8 @@ static int pegasus_probe(struct usb_interface *intf,
goto err_free_mem;
}
mutex_init(&pegasus->pm_mutex);
pegasus->usbdev = dev;
pegasus->dev = input_dev;
pegasus->intf = intf;
@ -388,10 +401,10 @@ static int pegasus_suspend(struct usb_interface *intf, pm_message_t message)
{
struct pegasus *pegasus = usb_get_intfdata(intf);
mutex_lock(&pegasus->dev->mutex);
mutex_lock(&pegasus->pm_mutex);
usb_kill_urb(pegasus->irq);
cancel_work_sync(&pegasus->init);
mutex_unlock(&pegasus->dev->mutex);
mutex_unlock(&pegasus->pm_mutex);
return 0;
}
@ -401,10 +414,10 @@ static int pegasus_resume(struct usb_interface *intf)
struct pegasus *pegasus = usb_get_intfdata(intf);
int retval = 0;
mutex_lock(&pegasus->dev->mutex);
mutex_lock(&pegasus->pm_mutex);
if (pegasus->dev->users && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
retval = -EIO;
mutex_unlock(&pegasus->dev->mutex);
mutex_unlock(&pegasus->pm_mutex);
return retval;
}
@ -414,14 +427,14 @@ static int pegasus_reset_resume(struct usb_interface *intf)
struct pegasus *pegasus = usb_get_intfdata(intf);
int retval = 0;
mutex_lock(&pegasus->dev->mutex);
mutex_lock(&pegasus->pm_mutex);
if (pegasus->dev->users) {
retval = pegasus_set_mode(pegasus, PEN_MODE_XY,
NOTETAKER_LED_MOUSE);
if (!retval && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
retval = -EIO;
}
mutex_unlock(&pegasus->dev->mutex);
mutex_unlock(&pegasus->pm_mutex);
return retval;
}