linux-kernel - Re: [PATCH 3/3] mfd: cros_ec: Add ACPI GPE handler for LID0 devices

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 4 Jan 2017 09:06:12 +0000
From:   Lee Jones <lee.jones@...aro.org>
To:     Thierry Escande <thierry.escande@...labora.com>
Cc:     Benson Leung <bleung@...omium.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] mfd: cros_ec: Add ACPI GPE handler for LID0 devices

On Fri, 16 Dec 2016, Thierry Escande wrote:

> From: Archana Patni <archana.patni@...el.com>
> 
> This patch installs an ACPI GPE handler for LID0 ACPI device to indicate
> ACPI core that this GPE should stay enabled for lid to work in suspend
> to idle path.
> 
> Signed-off-by: Archana Patni <archana.patni@...el.com>
> Signed-off-by: Thierry Escande <thierry.escande@...labora.com>
> ---
>  drivers/mfd/cros_ec.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 95 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> index b8a5080..628718e 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -17,6 +17,9 @@
>   * battery charging and regulator control, firmware update.
>   */
>  
> +#ifdef CONFIG_ACPI
> +#include <linux/acpi.h>
> +#endif

Please don't place #ifery in C files.

>  #include <linux/of_platform.h>
>  #include <linux/interrupt.h>
>  #include <linux/slab.h>
> @@ -29,6 +32,73 @@
>  #define CROS_EC_DEV_EC_INDEX 0
>  #define CROS_EC_DEV_PD_INDEX 1
>  
> +#ifdef CONFIG_ACPI

Remove this.

> +#define ACPI_LID_DEVICE      "LID0"
> +
> +static int ec_wake_gpe = -EINVAL;
> +
> +/*
> + * This handler indicates to ACPI core that this GPE should stay enabled for
> + * lid to work in suspend to idle path.
> + */
> +static u32 cros_ec_gpe_handler(acpi_handle gpe_device, u32 gpe_number,
> +			       void *data)
> +{
> +	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
> +}
> +
> +/*
> + * Get ACPI GPE for LID0 device.
> + */
> +static int cros_ec_get_ec_wake_gpe(struct device *dev)
> +{
> +	struct acpi_device *cros_acpi_dev;
> +	struct acpi_device *adev;
> +	acpi_handle handle;
> +	acpi_status status;
> +	int ret;
> +
> +	cros_acpi_dev = ACPI_COMPANION(dev);
> +
> +	if (!cros_acpi_dev || !cros_acpi_dev->parent ||
> +	   !cros_acpi_dev->parent->handle)
> +		return -EINVAL;
> +
> +	status = acpi_get_handle(cros_acpi_dev->parent->handle, ACPI_LID_DEVICE,
> +				 &handle);
> +	if (ACPI_FAILURE(status))
> +		return -EINVAL;
> +
> +	ret = acpi_bus_get_device(handle, &adev);
> +	if (ret)
> +		return ret;
> +
> +	return adev->wakeup.gpe_number;
> +}
> +
> +static int cros_ec_install_handler(struct device *dev)
> +{
> +	acpi_status status;
> +
> +	ec_wake_gpe = cros_ec_get_ec_wake_gpe(dev);
> +
> +	if (ec_wake_gpe < 0)
> +		return ec_wake_gpe;
> +
> +	status = acpi_install_gpe_handler(NULL, ec_wake_gpe,
> +					  ACPI_GPE_EDGE_TRIGGERED,
> +					  &cros_ec_gpe_handler, NULL);
> +	if (ACPI_FAILURE(status))
> +		return -ENODEV;
> +
> +	dev_info(dev, "Initialized, GPE = 0x%x\n", ec_wake_gpe);
> +
> +	return 0;
> +}
> +
> +#endif
> +
>  static struct cros_ec_platform ec_p = {
>  	.ec_name = CROS_EC_DEV_NAME,
>  	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
> @@ -166,6 +236,10 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>  
>  	dev_info(dev, "Chrome EC device registered\n");
>  
> +#ifdef CONFIG_ACPI
> +	cros_ec_install_handler(dev);
> +#endif

Here, just do:

	if (IS_ENABLED(CONFIG_ACPI))
		cros_ec_install_handler(dev);

And let the compiler take care of the rest.
	
>  	return 0;
>  
>  fail_mfd:
> @@ -179,6 +253,17 @@ int cros_ec_remove(struct cros_ec_device *ec_dev)
>  {
>  	mfd_remove_devices(ec_dev->dev);
>  
> +#ifdef CONFIG_ACPI
> +	if (ec_wake_gpe >= 0) {

	if (IS_ENABLED(CONFIG_ACPI) && ec_wake_gpe >= 0) {

> +		acpi_status status;
> +
> +		status = acpi_remove_gpe_handler(NULL, ec_wake_gpe,
> +						 &cros_ec_gpe_handler);
> +		if (ACPI_FAILURE(status))
> +			pr_err("failed to remove gpe handler\n");
> +	}
> +#endif
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL(cros_ec_remove);
> @@ -190,8 +275,16 @@ int cros_ec_suspend(struct cros_ec_device *ec_dev)
>  	int ret;
>  	u8 sleep_event;
>  
> -	sleep_event = pm_suspend_via_firmware() ? HOST_SLEEP_EVENT_S3_RESUME :
> -						  HOST_SLEEP_EVENT_S0IX_RESUME;
> +	if (!pm_suspend_via_firmware()) {
> +		sleep_event = HOST_SLEEP_EVENT_S0IX_SUSPEND;
> +#ifdef CONFIG_ACPI
> +		/* Clearing the GPE status for any pending event */
> +		if (ec_wake_gpe >= 0)

As above.

> +			acpi_clear_gpe(NULL, ec_wake_gpe);
> +#endif
> +	} else {
> +		sleep_event = HOST_SLEEP_EVENT_S3_SUSPEND;
> +	}
>  
>  	ret = cros_ec_sleep_event(ec_dev, sleep_event);
>  	if (ret < 0)

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog