Re: [PATCH 02/22] Input: ati_remote2 - use guard notation when acquiring mutex
From: Javier Carrasco
Date: Wed Sep 04 2024 - 14:50:06 EST
On 04/09/2024 06:42, Dmitry Torokhov wrote:
> Using guard notation makes the code more compact and error handling
> more robust by ensuring that mutexes are released in all code paths
> when control leaves critical section.
>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> ---
> drivers/input/misc/ati_remote2.c | 57 +++++++++++---------------------
> 1 file changed, 19 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/input/misc/ati_remote2.c b/drivers/input/misc/ati_remote2.c
> index 795f69edb4b2..e84649af801d 100644
> --- a/drivers/input/misc/ati_remote2.c
> +++ b/drivers/input/misc/ati_remote2.c
> @@ -244,29 +244,21 @@ static int ati_remote2_open(struct input_dev *idev)
> if (r) {
> dev_err(&ar2->intf[0]->dev,
> "%s(): usb_autopm_get_interface() = %d\n", __func__, r);
> - goto fail1;
> + return r;
> }
>
> - mutex_lock(&ati_remote2_mutex);
> + scoped_guard(mutex, &ati_remote2_mutex) {
> + if (!(ar2->flags & ATI_REMOTE2_SUSPENDED)) {
> + r = ati_remote2_submit_urbs(ar2);
> + if (r)
> + break;
> + }
>
> - if (!(ar2->flags & ATI_REMOTE2_SUSPENDED)) {
> - r = ati_remote2_submit_urbs(ar2);
> - if (r)
> - goto fail2;
> + ar2->flags |= ATI_REMOTE2_OPENED;
> }
>
> - ar2->flags |= ATI_REMOTE2_OPENED;
> -
> - mutex_unlock(&ati_remote2_mutex);
> -
> usb_autopm_put_interface(ar2->intf[0]);
>
> - return 0;
> -
> - fail2:
> - mutex_unlock(&ati_remote2_mutex);
> - usb_autopm_put_interface(ar2->intf[0]);
> - fail1:
> return r;
> }
>
> @@ -276,14 +268,12 @@ static void ati_remote2_close(struct input_dev *idev)
>
> dev_dbg(&ar2->intf[0]->dev, "%s()\n", __func__);
>
> - mutex_lock(&ati_remote2_mutex);
> + guard(mutex)(&ati_remote2_mutex);
>
> if (!(ar2->flags & ATI_REMOTE2_SUSPENDED))
> ati_remote2_kill_urbs(ar2);
>
> ar2->flags &= ~ATI_REMOTE2_OPENED;
> -
> - mutex_unlock(&ati_remote2_mutex);
> }
>
> static void ati_remote2_input_mouse(struct ati_remote2 *ar2)
> @@ -713,16 +703,14 @@ static ssize_t ati_remote2_store_channel_mask(struct device *dev,
> return r;
> }
>
> - mutex_lock(&ati_remote2_mutex);
> -
> - if (mask != ar2->channel_mask) {
> - r = ati_remote2_setup(ar2, mask);
> - if (!r)
> - ar2->channel_mask = mask;
> + scoped_guard(mutex, &ati_remote2_mutex) {
> + if (mask != ar2->channel_mask) {
> + r = ati_remote2_setup(ar2, mask);
> + if (!r)
> + ar2->channel_mask = mask;
> + }
> }
>
> - mutex_unlock(&ati_remote2_mutex);
> -
> usb_autopm_put_interface(ar2->intf[0]);
>
> return r ? r : count;
> @@ -892,15 +880,13 @@ static int ati_remote2_suspend(struct usb_interface *interface,
>
> dev_dbg(&ar2->intf[0]->dev, "%s()\n", __func__);
>
> - mutex_lock(&ati_remote2_mutex);
> + guard(mutex)(&ati_remote2_mutex);
>
> if (ar2->flags & ATI_REMOTE2_OPENED)
> ati_remote2_kill_urbs(ar2);
>
> ar2->flags |= ATI_REMOTE2_SUSPENDED;
>
> - mutex_unlock(&ati_remote2_mutex);
> -
> return 0;
> }
>
> @@ -917,7 +903,7 @@ static int ati_remote2_resume(struct usb_interface *interface)
>
> dev_dbg(&ar2->intf[0]->dev, "%s()\n", __func__);
>
> - mutex_lock(&ati_remote2_mutex);
> + guard(mutex)(&ati_remote2_mutex);
>
> if (ar2->flags & ATI_REMOTE2_OPENED)
> r = ati_remote2_submit_urbs(ar2);
> @@ -925,8 +911,6 @@ static int ati_remote2_resume(struct usb_interface *interface)
> if (!r)
> ar2->flags &= ~ATI_REMOTE2_SUSPENDED;
>
> - mutex_unlock(&ati_remote2_mutex);
> -
> return r;
> }
>
> @@ -943,11 +927,11 @@ static int ati_remote2_reset_resume(struct usb_interface *interface)
>
> dev_dbg(&ar2->intf[0]->dev, "%s()\n", __func__);
>
> - mutex_lock(&ati_remote2_mutex);
> + guard(mutex)(&ati_remote2_mutex);
>
> r = ati_remote2_setup(ar2, ar2->channel_mask);
> if (r)
> - goto out;
> + return r;
>
> if (ar2->flags & ATI_REMOTE2_OPENED)
> r = ati_remote2_submit_urbs(ar2);
> @@ -955,9 +939,6 @@ static int ati_remote2_reset_resume(struct usb_interface *interface)
> if (!r)
> ar2->flags &= ~ATI_REMOTE2_SUSPENDED;
>
> - out:
> - mutex_unlock(&ati_remote2_mutex);
> -
> return r;
> }
>
Reviewed-by: Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx>