Re: [PATCH 3/4] asus-wmi: Add egpu enable method

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 7/17/21 10:13 AM, Luke D. Jones wrote:
> The X13 Flow laptops can utilise an external GPU. This requires
> toggling an ACPI method which will first disable the internal
> dGPU, and then enable the eGPU.
> 
> Signed-off-by: Luke D. Jones <luke@ljones.dev>
> ---
>  drivers/platform/x86/asus-wmi.c            | 91 ++++++++++++++++++++++
>  include/linux/platform_data/x86/asus-wmi.h |  3 +
>  2 files changed, 94 insertions(+)
> 
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 02762a60d27a..ee5d8656641e 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -210,6 +210,9 @@ struct asus_wmi {
>  	u8 fan_boost_mode_mask;
>  	u8 fan_boost_mode;
>  
> +	bool egpu_enable_available; // 0 = enable
> +	bool egpu_enable;
> +
>  	bool dgpu_disable_available;
>  	bool dgpu_disable;
>  
> @@ -430,6 +433,86 @@ static void lid_flip_tablet_mode_get_state(struct asus_wmi *asus)
>  	}
>  }
>  
> +/* eGPU ********************************************************************/
> +static int egpu_enable_check_present(struct asus_wmi *asus)
> +{
> +	u32 result;
> +	int err;
> +
> +	asus->egpu_enable_available = false;
> +
> +	err = asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_EGPU, &result);
> +	if (err) {
> +		if (err == -ENODEV)
> +			return 0;
> +		return err;
> +	}
> +
> +	if (result & ASUS_WMI_DSTS_PRESENCE_BIT) {
> +		asus->egpu_enable_available = true;
> +		asus->egpu_enable = result & ASUS_WMI_DSTS_STATUS_BIT;
> +	}
> +
> +	return 0;
> +}
> +
> +static int egpu_enable_write(struct asus_wmi *asus)
> +{
> +	int err;
> +	u8 value;
> +	u32 retval;

Upside-down-christmastree declaration order please.

> +
> +	value = asus->egpu_enable;
> +
> +	err = asus_wmi_set_devstate(ASUS_WMI_DEVID_EGPU, value, &retval);
> +
> +	if (err) {
> +		pr_warn("Failed to set egpu disable: %d\n", err);
> +		return err;
> +	}
> +
> +	if (retval > 1 || retval < 0) {
> +		pr_warn("Failed to set egpu disable (retval): 0x%x\n", retval);
> +		return -EIO;
> +	}
> +
> +	sysfs_notify(&asus->platform_device->dev.kobj, NULL, "egpu_enable");
> +
> +	return 0;
> +}
> +
> +static ssize_t egpu_enable_show(struct device *dev,
> +				   struct device_attribute *attr, char *buf)
> +{
> +	struct asus_wmi *asus = dev_get_drvdata(dev);
> +	bool mode = asus->egpu_enable;

Drop the unnecessary "mode" local variable please.

> +
> +	return sysfs_emit(buf, "%d\n", mode);
> +}
> +
> +static ssize_t egpu_enable_store(struct device *dev,
> +				    struct device_attribute *attr,
> +				    const char *buf, size_t count)
> +{
> +	int result;
> +	bool disable;
> +	struct asus_wmi *asus = dev_get_drvdata(dev);

Upside-down-christmastree declaration order please.

> +
> +	result = kstrtobool(buf, &disable);
> +	if (result == -EINVAL)
> +		return result;

Just "if (result) ..." please.

> +
> +	asus->egpu_enable = disable;
> +
> +	result = egpu_enable_write(asus);
> +	if (result != 0)
> +		return result;
> +
> +	return count;
> +}
> +
> +static DEVICE_ATTR_RW(egpu_enable);
> +
>  /* dGPU ********************************************************************/
>  static int dgpu_disable_check_present(struct asus_wmi *asus)
>  {
> @@ -2502,6 +2585,7 @@ static struct attribute *platform_attributes[] = {
>  	&dev_attr_camera.attr,
>  	&dev_attr_cardr.attr,
>  	&dev_attr_touchpad.attr,
> +	&dev_attr_egpu_enable.attr,
>  	&dev_attr_dgpu_disable.attr,
>  	&dev_attr_lid_resume.attr,
>  	&dev_attr_als_enable.attr,
> @@ -2529,6 +2613,8 @@ static umode_t asus_sysfs_is_visible(struct kobject *kobj,
>  		devid = ASUS_WMI_DEVID_LID_RESUME;
>  	else if (attr == &dev_attr_als_enable.attr)
>  		devid = ASUS_WMI_DEVID_ALS_ENABLE;
> +	else if (attr == &dev_attr_egpu_enable.attr)
> +		ok = asus->egpu_enable_available;
>  	else if (attr == &dev_attr_dgpu_disable.attr)
>  		ok = asus->dgpu_disable_available;
>  	else if (attr == &dev_attr_fan_boost_mode.attr)
> @@ -2792,6 +2878,10 @@ static int asus_wmi_add(struct platform_device *pdev)
>  	if (err)
>  		goto fail_platform;
>  
> +	err = egpu_enable_check_present(asus);
> +	if (err)
> +		goto fail_egpu_enable;
> +
>  	err = dgpu_disable_check_present(asus);
>  	if (err)
>  		goto fail_dgpu_disable;
> @@ -2896,6 +2986,7 @@ static int asus_wmi_add(struct platform_device *pdev)
>  fail_sysfs:
>  fail_throttle_thermal_policy:
>  fail_fan_boost_mode:
> +fail_egpu_enable:
>  fail_dgpu_disable:
>  fail_platform:
>  fail_panel_od:
> diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
> index a528f9d0e4b7..17dc5cb6f3f2 100644
> --- a/include/linux/platform_data/x86/asus-wmi.h
> +++ b/include/linux/platform_data/x86/asus-wmi.h
> @@ -90,6 +90,9 @@
>  /* Keyboard dock */
>  #define ASUS_WMI_DEVID_KBD_DOCK		0x00120063
>  
> +/* dgpu on/off */
> +#define ASUS_WMI_DEVID_EGPU		0x00090019
> +
>  /* dgpu on/off */
>  #define ASUS_WMI_DEVID_DGPU		0x00090020
>  
> 

Regards,

Hans