linux-kernel - Re: [PATCH 1/2] gpiolib: acpi: Add support to ignore programming an interrupt

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Message-ID: <4370433d-c2b7-ee00-e3cf-5389f6914e4c@redhat.com>
Date:   Wed, 27 Jul 2022 15:15:15 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     Mario Limonciello <mario.limonciello@....com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>
Cc:     Pavel Krc <reg.krn@...c.net>, linux-gpio@...r.kernel.org,
        linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] gpiolib: acpi: Add support to ignore programming an
 interrupt

Hi,

On 7/19/22 16:21, Mario Limonciello wrote:
> gpiolib-acpi already had support for ignoring a pin for wakeup, but
> if an OEM configures a floating pin as an interrupt source then
> stopping it from being a wakeup won't do much good to stop the
> interrupt storm.
> 
> Add support for a module parameter and quirk infrastructure to
> ignore interrupts as well.
> 
> Tested-by: Pavel Krc <reg.krn@...c.net>
> Signed-off-by: Mario Limonciello <mario.limonciello@....com>
> ---
>  drivers/gpio/gpiolib-acpi.c | 39 ++++++++++++++++++++++++++++++++-----
>  1 file changed, 34 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
> index c2523ac26fac..375942d92d6f 100644
> --- a/drivers/gpio/gpiolib-acpi.c
> +++ b/drivers/gpio/gpiolib-acpi.c
> @@ -32,9 +32,21 @@ MODULE_PARM_DESC(ignore_wake,
>  		 "controller@pin combos on which to ignore the ACPI wake flag "
>  		 "ignore_wake=controller@pin[,controller@pin[,...]]");
>  
> +static char *ignore_interrupt;
> +module_param(ignore_interrupt, charp, 0444);
> +MODULE_PARM_DESC(ignore_interrupt,
> +		 "controller@pin combos on which to ignore interrupt "
> +		 "ignore_interrupt=controller@pin[,controller@pin[,...]]");
> +
>  struct acpi_gpiolib_dmi_quirk {
>  	bool no_edge_events_on_boot;
>  	char *ignore_wake;
> +	char *ignore_interrupt;
> +};
> +
> +enum ignore_type {
> +	IGNORE_WAKEUP,
> +	IGNORE_INTERRUPT,
>  };

Please drop the enum; and ...

>  
>  /**
> @@ -317,14 +329,18 @@ static struct gpio_desc *acpi_request_own_gpiod(struct gpio_chip *chip,
>  	return desc;
>  }
>  
> -static bool acpi_gpio_in_ignore_list(const char *controller_in, unsigned int pin_in)
> +static bool acpi_gpio_in_ignore_list(const char *controller_in, unsigned int pin_in,
> +				     enum ignore_type type)
>  {

make the prototype:

static bool acpi_gpio_in_ignore_list(const char *ignore_list, const char *controller_in, unsigned int pin_in)

and ...

> -	const char *controller, *pin_str;
> +	const char *controller = NULL, *pin_str;
>  	unsigned int pin;
>  	char *endp;
>  	int len;
>  
> -	controller = ignore_wake;
> +	if (type == IGNORE_WAKEUP)
> +		controller = ignore_wake;
> +	else if (type == IGNORE_INTERRUPT)
> +		controller = ignore_interrupt;

Use:

	controller = ignore_list;

here; and ...

>  	while (controller) {
>  		pin_str = strchr(controller, '@');
>  		if (!pin_str)
> @@ -348,7 +364,12 @@ static bool acpi_gpio_in_ignore_list(const char *controller_in, unsigned int pin
>  
>  	return false;
>  err:
> -	pr_err_once("Error: Invalid value for gpiolib_acpi.ignore_wake: %s\n", ignore_wake);
> +	if (type == IGNORE_WAKEUP)
> +		pr_err_once("Error: Invalid value for gpiolib_acpi.ignore_wake: %s\n",
> +			    ignore_wake);
> +	else if (type == IGNORE_INTERRUPT)
> +		pr_err_once("Error: Invalid value for gpiolib_acpi.ignore_interrupt: %s\n",
> +			    ignore_interrupt);

change this to:

	pr_err_once("Error: Invalid value for gpiolib_acpi.ignore_...: %s\n", ignore_list);

and ...

>  	return false;
>  }
>  
> @@ -360,7 +381,7 @@ static bool acpi_gpio_irq_is_wake(struct device *parent,
>  	if (agpio->wake_capable != ACPI_WAKE_CAPABLE)
>  		return false;
>  
> -	if (acpi_gpio_in_ignore_list(dev_name(parent), pin)) {
> +	if (acpi_gpio_in_ignore_list(dev_name(parent), pin, IGNORE_WAKEUP)) {

adjust this to:

	if (acpi_gpio_in_ignore_list(ignore_wakeup, dev_name(parent), pin)) {

and ...

>  		dev_info(parent, "Ignoring wakeup on pin %u\n", pin);
>  		return false;
>  	}
> @@ -427,6 +448,11 @@ static acpi_status acpi_gpiochip_alloc_event(struct acpi_resource *ares,
>  		goto fail_unlock_irq;
>  	}
>  
> +	if (acpi_gpio_in_ignore_list(dev_name(chip->parent), pin, IGNORE_INTERRUPT)) {

this line to:

	if (acpi_gpio_in_ignore_list(ignore_interrupt, dev_name(parent), pin)) {

That IMHO is a cleaner way to handle this then introducing the enum type +
enum parameter to acpi_gpio_in_ignore_list().

Regards,

Hans



> +		dev_info(chip->parent, "Ignoring interrupt on pin %u\n", pin);
> +		return AE_OK;
> +	}
> +
>  	event = kzalloc(sizeof(*event), GFP_KERNEL);
>  	if (!event)
>  		goto fail_unlock_irq;
> @@ -1582,6 +1608,9 @@ static int __init acpi_gpio_setup_params(void)
>  	if (ignore_wake == NULL && quirk && quirk->ignore_wake)
>  		ignore_wake = quirk->ignore_wake;
>  
> +	if (ignore_interrupt == NULL && quirk && quirk->ignore_interrupt)
> +		ignore_interrupt = quirk->ignore_interrupt;
> +
>  	return 0;
>  }
>