Re: [RESEND PATCH 4/6] input: pegasus_notetaker: do not rely on input_dev->users

Dmitry Torokhov
2018-03-17T18:11:13Z

On Wed, Feb 28, 2018 at 02:38:01PM +0100, Marcus Folkesson wrote:
> 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.folkesson@gmail.com>

Applied, thank you.

> ---
> 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)
> --
> 2.16.2
>

--
Dmitry