2023-12-01 13:13:41

by Marcus Folkesson

Subject: [PATCH v2] Input: pxrc - simplify mutex handling with guard macro

Use the guard(mutex) macro for handle mutex lock/unlocks.

Signed-off-by: Marcus Folkesson <[email protected]>
---
Changes in v2:
- Add guard in pxrc_open()
- Link to v1: https://lore.kernel.org/r/[email protected]
---
drivers/input/joystick/pxrc.c | 29 ++++++++++++-----------------
1 file changed, 12 insertions(+), 17 deletions(-)

diff --git a/drivers/input/joystick/pxrc.c b/drivers/input/joystick/pxrc.c
index ea2bf5951d67..d4b699418361 100644
--- a/drivers/input/joystick/pxrc.c
+++ b/drivers/input/joystick/pxrc.c
@@ -5,15 +5,17 @@
* Copyright (C) 2018 Marcus Folkesson <[email protected]>
*/

-#include <linux/kernel.h>
+#include <linux/cleanup.h>
#include <linux/errno.h>
-#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
#include <linux/uaccess.h>
+
#include <linux/usb.h>
#include <linux/usb/input.h>
-#include <linux/mutex.h>
-#include <linux/input.h>

#define PXRC_VENDOR_ID 0x1781
#define PXRC_PRODUCT_ID 0x0898
@@ -83,31 +85,26 @@ static int pxrc_open(struct input_dev *input)
struct pxrc *pxrc = input_get_drvdata(input);
int retval;

- mutex_lock(&pxrc->pm_mutex);
+ guard(mutex)(&pxrc->pm_mutex);
retval = usb_submit_urb(pxrc->urb, GFP_KERNEL);
if (retval) {
dev_err(&pxrc->intf->dev,
"%s - usb_submit_urb failed, error: %d\n",
__func__, retval);
- retval = -EIO;
- goto out;
+ return -EIO;
}

pxrc->is_open = true;
-
-out:
- mutex_unlock(&pxrc->pm_mutex);
- return retval;
+ return 0;
}

static void pxrc_close(struct input_dev *input)
{
struct pxrc *pxrc = input_get_drvdata(input);

- mutex_lock(&pxrc->pm_mutex);
+ guard(mutex)(&pxrc->pm_mutex);
usb_kill_urb(pxrc->urb);
pxrc->is_open = false;
- mutex_unlock(&pxrc->pm_mutex);
}

static void pxrc_free_urb(void *_pxrc)
@@ -208,10 +205,9 @@ static int pxrc_suspend(struct usb_interface *intf, pm_message_t message)
{
struct pxrc *pxrc = usb_get_intfdata(intf);

- mutex_lock(&pxrc->pm_mutex);
+ guard(mutex)(&pxrc->pm_mutex);
if (pxrc->is_open)
usb_kill_urb(pxrc->urb);
- mutex_unlock(&pxrc->pm_mutex);

return 0;
}
@@ -221,11 +217,10 @@ static int pxrc_resume(struct usb_interface *intf)
struct pxrc *pxrc = usb_get_intfdata(intf);
int retval = 0;

- mutex_lock(&pxrc->pm_mutex);
+ guard(mutex)(&pxrc->pm_mutex);
if (pxrc->is_open && usb_submit_urb(pxrc->urb, GFP_KERNEL) < 0)
retval = -EIO;

- mutex_unlock(&pxrc->pm_mutex);
return retval;
}


---
base-commit: ffc253263a1375a65fa6c9f62a893e9767fbebfa
change-id: 20231201-pxrc-guard-03dc35771b36

Best regards,
--
Marcus Folkesson <[email protected]>

2023-12-01 23:36:15

by Dmitry Torokhov

Subject: Re: [PATCH v2] Input: pxrc - simplify mutex handling with guard macro

On Fri, Dec 01, 2023 at 02:17:13PM +0100, Marcus Folkesson wrote:
> Use the guard(mutex) macro for handle mutex lock/unlocks.
>
> Signed-off-by: Marcus Folkesson <[email protected]>
> ---
> Changes in v2:
> - Add guard in pxrc_open()
> - Link to v1: https://lore.kernel.org/r/[email protected]
> ---
> drivers/input/joystick/pxrc.c | 29 ++++++++++++-----------------
> 1 file changed, 12 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/input/joystick/pxrc.c b/drivers/input/joystick/pxrc.c
> index ea2bf5951d67..d4b699418361 100644
> --- a/drivers/input/joystick/pxrc.c
> +++ b/drivers/input/joystick/pxrc.c
> @@ -5,15 +5,17 @@
> * Copyright (C) 2018 Marcus Folkesson <[email protected]>
> */
>
> -#include <linux/kernel.h>
> +#include <linux/cleanup.h>
> #include <linux/errno.h>
> -#include <linux/slab.h>
> +#include <linux/input.h>
> +#include <linux/kernel.h>
> #include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> #include <linux/uaccess.h>
> +
> #include <linux/usb.h>
> #include <linux/usb/input.h>
> -#include <linux/mutex.h>
> -#include <linux/input.h>
>
> #define PXRC_VENDOR_ID 0x1781
> #define PXRC_PRODUCT_ID 0x0898
> @@ -83,31 +85,26 @@ static int pxrc_open(struct input_dev *input)
> struct pxrc *pxrc = input_get_drvdata(input);
> int retval;

Now that we are not returning "success" and only carry error codes
in this variable we should call it "error".

>
> - mutex_lock(&pxrc->pm_mutex);
> + guard(mutex)(&pxrc->pm_mutex);
> retval = usb_submit_urb(pxrc->urb, GFP_KERNEL);
> if (retval) {
> dev_err(&pxrc->intf->dev,
> "%s - usb_submit_urb failed, error: %d\n",
> __func__, retval);
> - retval = -EIO;
> - goto out;
> + return -EIO;
> }
>
> pxrc->is_open = true;
> -
> -out:
> - mutex_unlock(&pxrc->pm_mutex);
> - return retval;
> + return 0;
> }
>
> static void pxrc_close(struct input_dev *input)
> {
> struct pxrc *pxrc = input_get_drvdata(input);
>
> - mutex_lock(&pxrc->pm_mutex);
> + guard(mutex)(&pxrc->pm_mutex);
> usb_kill_urb(pxrc->urb);
> pxrc->is_open = false;
> - mutex_unlock(&pxrc->pm_mutex);
> }
>
> static void pxrc_free_urb(void *_pxrc)
> @@ -208,10 +205,9 @@ static int pxrc_suspend(struct usb_interface *intf, pm_message_t message)
> {
> struct pxrc *pxrc = usb_get_intfdata(intf);
>
> - mutex_lock(&pxrc->pm_mutex);
> + guard(mutex)(&pxrc->pm_mutex);
> if (pxrc->is_open)
> usb_kill_urb(pxrc->urb);
> - mutex_unlock(&pxrc->pm_mutex);
>
> return 0;
> }
> @@ -221,11 +217,10 @@ static int pxrc_resume(struct usb_interface *intf)
> struct pxrc *pxrc = usb_get_intfdata(intf);
> int retval = 0;
>
> - mutex_lock(&pxrc->pm_mutex);
> + guard(mutex)(&pxrc->pm_mutex);
> if (pxrc->is_open && usb_submit_urb(pxrc->urb, GFP_KERNEL) < 0)
> retval = -EIO;

return -EIO;
>
> - mutex_unlock(&pxrc->pm_mutex);
> return retval;

return 0;

Thanks.

--
Dmitry