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| author |   Marcus Folkesson <marcus.folkesson@gmail.com> | 2018-03-17 10:54:13 -0700 |
|---|---|---|
| committer |   Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2018-03-26 15:22:16 -0700 |
| commit | 85f46fbf5e242ef923fd313722e65cb6d2170149 (patch) | |
| tree | a20e6021842e99f6a828a3cb3a4529e36cf2f257 | |
| parent | Input: usbtouchscreen - fix deadlock in autosuspend (diff) | |
| download | linux-dev-85f46fbf5e242ef923fd313722e65cb6d2170149.tar.xz linux-dev-85f46fbf5e242ef923fd313722e65cb6d2170149.zip | |
Input: usbtouchscreen - do not rely on input_dev->users
If the device is unused and suspended, a call to open will cause the
device to autoresume through the call to usb_autopm_get_interface().
input_dev->users is already incremented by the input subsystem,
therefore this expression will always be evaluated to true:
if (input->users || usbtouch->type->irq_always)
result = usb_submit_urb(usbtouch->irq, GFP_NOIO);
The same URB will then be fail when resubmitted in usbtouch_open().
Introduce usbtouch->is_open to keep track of the state instead.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
| -rw-r--r-- | drivers/input/touchscreen/usbtouchscreen.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/input/touchscreen/usbtouchscreen.c b/drivers/input/touchscreen/usbtouchscreen.c index d15a7e2d9bbf..c6cf90868503 100644 --- a/drivers/input/touchscreen/usbtouchscreen.c +++ b/drivers/input/touchscreen/usbtouchscreen.c @@ -109,6 +109,7 @@ struct usbtouch_usb { struct input_dev *input; struct usbtouch_device_info *type; struct mutex pm_mutex; /* serialize access to open/suspend */ + bool is_open; char name[128]; char phys[64]; void *priv; @@ -1461,6 +1462,7 @@ static int usbtouch_open(struct input_dev *input) } usbtouch->interface->needs_remote_wakeup = 1; + usbtouch->is_open = true; out_put: mutex_unlock(&usbtouch->pm_mutex); usb_autopm_put_interface(usbtouch->interface); @@ -1476,6 +1478,7 @@ static void usbtouch_close(struct input_dev *input) mutex_lock(&usbtouch->pm_mutex); if (!usbtouch->type->irq_always) usb_kill_urb(usbtouch->irq); + usbtouch->is_open = false; mutex_unlock(&usbtouch->pm_mutex); r = usb_autopm_get_interface(usbtouch->interface); @@ -1497,11 +1500,10 @@ static int usbtouch_suspend static int usbtouch_resume(struct usb_interface *intf) { struct usbtouch_usb *usbtouch = usb_get_intfdata(intf); - struct input_dev *input = usbtouch->input; int result = 0; mutex_lock(&usbtouch->pm_mutex); - if (input->users || usbtouch->type->irq_always) + if (usbtouch->is_open || usbtouch->type->irq_always) result = usb_submit_urb(usbtouch->irq, GFP_NOIO); mutex_unlock(&usbtouch->pm_mutex); @@ -1511,7 +1513,6 @@ static int usbtouch_resume(struct usb_interface *intf) static int usbtouch_reset_resume(struct usb_interface *intf) { struct usbtouch_usb *usbtouch = usb_get_intfdata(intf); - struct input_dev *input = usbtouch->input; int err = 0; /* reinit the device */ @@ -1527,7 +1528,7 @@ static int usbtouch_reset_resume(struct usb_interface *intf) /* restart IO if needed */ mutex_lock(&usbtouch->pm_mutex); - if (input->users) + if (usbtouch->is_open) err = usb_submit_urb(usbtouch->irq, GFP_NOIO); mutex_unlock(&usbtouch->pm_mutex); |