[PATCH 2/2] input: pegasus_notetaker: do not rely on input_dev->users

[Marcus Folkesson]

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 (pegasus->dev->users && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
                retval = -EIO;

The same URB will then be fail when resubmitted in pegasus_open().

Introduce pegasus->is_open to keep track of the state instead.

Signed-off-by: Marcus Folkesson <marcus.folkes...@gmail.com>
---
 drivers/input/tablet/pegasus_notetaker.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/input/tablet/pegasus_notetaker.c 
b/drivers/input/tablet/pegasus_notetaker.c
index 9ab1ed5e20e7..74c93e09c337 100644
--- a/drivers/input/tablet/pegasus_notetaker.c
+++ b/drivers/input/tablet/pegasus_notetaker.c
@@ -80,6 +80,7 @@ struct pegasus {
 
        /* serialize access to open/suspend */
        struct mutex pm_mutex;
+       bool is_open;
 
        char name[128];
        char phys[64];
@@ -232,6 +233,7 @@ static int pegasus_open(struct input_dev *dev)
        if (error)
                goto err_kill_urb;
 
+       pegasus->is_open = 1;
        mutex_unlock(&pegasus->pm_mutex);
        return 0;
 
@@ -251,6 +253,7 @@ static void pegasus_close(struct input_dev *dev)
        mutex_lock(&pegasus->pm_mutex);
        usb_kill_urb(pegasus->irq);
        cancel_work_sync(&pegasus->init);
+       pegasus->is_open = 0;
        mutex_unlock(&pegasus->pm_mutex);
 
        usb_autopm_put_interface(pegasus->intf);
@@ -415,7 +418,7 @@ static int pegasus_resume(struct usb_interface *intf)
        int retval = 0;
 
        mutex_lock(&pegasus->pm_mutex);
-       if (pegasus->dev->users && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
+       if (pegasus->is_open && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
                retval = -EIO;
        mutex_unlock(&pegasus->pm_mutex);
 
@@ -428,7 +431,7 @@ static int pegasus_reset_resume(struct usb_interface *intf)
        int retval = 0;
 
        mutex_lock(&pegasus->pm_mutex);
-       if (pegasus->dev->users) {
+       if (pegasus->is_open) {
                retval = pegasus_set_mode(pegasus, PEN_MODE_XY,
                                          NOTETAKER_LED_MOUSE);
                if (!retval && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
-- 
2.15.1