| Message ID | 20240220111019.133697-2-herve.codina@bootlin.com |
|---|---|
| State | New |
| Headers | show |
| Series | gpio-cdev: Release IRQ used by gpio-cdev on gpio chip removal | expand |
On Tue, Feb 20, 2024 at 12:10 PM Herve Codina <herve.codina@bootlin.com> wrote: > > When gpio chip device is removed while some related gpio are used by the > user-space, the following warning can appear: > remove_proc_entry: removing non-empty directory 'irq/233', leaking at least 'gpiomon' > WARNING: CPU: 2 PID: 72 at fs/proc/generic.c:717 remove_proc_entry+0x190/0x19c > ... > Call trace: > remove_proc_entry+0x190/0x19c > unregister_irq_proc+0xd0/0x104 > free_desc+0x4c/0xc4 > irq_free_descs+0x6c/0x90 > irq_dispose_mapping+0x104/0x14c > gpiochip_irqchip_remove+0xcc/0x1a4 > gpiochip_remove+0x48/0x100 > ... > > Indeed, the gpio cdev uses an IRQ but this IRQ is not released > (irq_free() call) before the call to gpiochip_irqchip_remove(). > > In order to give a chance to the gpio dev driver to release this > irq before removing the IRQ mapping, notify the cdev driver about > the gpio device removal before the gpiochip_irqchip_remove() call. > > Signed-off-by: Herve Codina <herve.codina@bootlin.com> > --- > drivers/gpio/gpiolib.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index 8b3a0f45b574..079181b9daa8 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -1051,6 +1051,13 @@ void gpiochip_remove(struct gpio_chip *gc) > > /* FIXME: should the legacy sysfs handling be moved to gpio_device? */ > gpiochip_sysfs_unregister(gdev); > + > + /* > + * Tell gcdev that the device is removing. If any gpio resources are in > + * use (irqs for instance), it's time for gcdev to release them. > + */ > + gcdev_unregister(gdev); > + > gpiochip_free_hogs(gc); > /* Numb the device, cancelling all outstanding operations */ > gdev->chip = NULL; > @@ -1085,7 +1092,6 @@ void gpiochip_remove(struct gpio_chip *gc) > * be removed, else it will be dangling until the last user is > * gone. > */ > - gcdev_unregister(gdev); > up_write(&gdev->sem); Please rebase it on top of the for-next branch of the GPIO tree. We've had some significant rework recently, we no longer even have this semaphore. Bart > gpio_device_put(gdev); > } > -- > 2.43.0 >
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 8b3a0f45b574..079181b9daa8 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1051,6 +1051,13 @@ void gpiochip_remove(struct gpio_chip *gc) /* FIXME: should the legacy sysfs handling be moved to gpio_device? */ gpiochip_sysfs_unregister(gdev); + + /* + * Tell gcdev that the device is removing. If any gpio resources are in + * use (irqs for instance), it's time for gcdev to release them. + */ + gcdev_unregister(gdev); + gpiochip_free_hogs(gc); /* Numb the device, cancelling all outstanding operations */ gdev->chip = NULL; @@ -1085,7 +1092,6 @@ void gpiochip_remove(struct gpio_chip *gc) * be removed, else it will be dangling until the last user is * gone. */ - gcdev_unregister(gdev); up_write(&gdev->sem); gpio_device_put(gdev); }
When gpio chip device is removed while some related gpio are used by the user-space, the following warning can appear: remove_proc_entry: removing non-empty directory 'irq/233', leaking at least 'gpiomon' WARNING: CPU: 2 PID: 72 at fs/proc/generic.c:717 remove_proc_entry+0x190/0x19c ... Call trace: remove_proc_entry+0x190/0x19c unregister_irq_proc+0xd0/0x104 free_desc+0x4c/0xc4 irq_free_descs+0x6c/0x90 irq_dispose_mapping+0x104/0x14c gpiochip_irqchip_remove+0xcc/0x1a4 gpiochip_remove+0x48/0x100 ... Indeed, the gpio cdev uses an IRQ but this IRQ is not released (irq_free() call) before the call to gpiochip_irqchip_remove(). In order to give a chance to the gpio dev driver to release this irq before removing the IRQ mapping, notify the cdev driver about the gpio device removal before the gpiochip_irqchip_remove() call. Signed-off-by: Herve Codina <herve.codina@bootlin.com> --- drivers/gpio/gpiolib.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)