Re: [PATCH v2 1/1] platform/x86: asus-wmi: disable USB0 hub on ROG Ally before suspend

[Hans de Goede]

Hi,

On 11/27/23 00:05, Luke D. Jones wrote:
> ASUS have worked around an issue in XInput where it doesn't support USB
> selective suspend, which causes suspend issues in Windows. They worked
> around this by adjusting the MCU firmware to disable the USB0 hub when
> the screen is switched off during the Microsoft DSM suspend path in ACPI.
> 
> The issue we have with this however is one of timing - the call the tells
> the MCU to this isn't able to complete before suspend is done so we call
> this in a prepare() and add a small msleep() to ensure it is done. This
> must be done before the screen is switched off to prevent a variety of
> possible races.
> 
> Further to this the MCU powersave option must also be disabled as it can
> cause a number of issues such as:
> - unreliable resume connection of N-Key
> - complete loss of N-Key if the power is plugged in while suspended
> Disabling the powersave option prevents this.
> 
> Without this the MCU is unable to initialise itself correctly on resume.
> 
> Signed-off-by: Luke D. Jones <luke@xxxxxxxxxx>

Thanks, patch looks good to me, except that all the new lines
seem to use 4 spaces rather then a tab char as indent.

With that fixed you can add my:

Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>

to the next version.

Regards,

Hans


> ---
>  drivers/platform/x86/asus-wmi.c            | 50 ++++++++++++++++++++++
>  include/linux/platform_data/x86/asus-wmi.h |  3 ++
>  2 files changed, 53 insertions(+)
> 
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 6a79f16233ab..4ba33dfebfd4 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -16,6 +16,7 @@
>  #include <linux/acpi.h>
>  #include <linux/backlight.h>
>  #include <linux/debugfs.h>
> +#include <linux/delay.h>
>  #include <linux/dmi.h>
>  #include <linux/fb.h>
>  #include <linux/hwmon.h>
> @@ -132,6 +133,11 @@ module_param(fnlock_default, bool, 0444);
>  #define ASUS_SCREENPAD_BRIGHT_MAX 255
>  #define ASUS_SCREENPAD_BRIGHT_DEFAULT 60
>  
> +/* Controls the power state of the USB0 hub on ROG Ally which input is on */
> +#define ASUS_USB0_PWR_EC0_CSEE "\\_SB.PCI0.SBRG.EC0.CSEE"
> +/* 300ms so far seems to produce a reliable result on AC and battery */
> +#define ASUS_USB0_PWR_EC0_CSEE_WAIT 300
> +
>  static const char * const ashs_ids[] = { "ATK4001", "ATK4002", NULL };
>  
>  static int throttle_thermal_policy_write(struct asus_wmi *);
> @@ -300,6 +306,9 @@ struct asus_wmi {
>  
>  	bool fnlock_locked;
>  
> +	/* The ROG Ally device requires the MCU USB device be disconnected before suspend */
> +	bool ally_mcu_usb_switch;
> +
>  	struct asus_wmi_debug debug;
>  
>  	struct asus_wmi_driver *driver;
> @@ -4488,6 +4497,8 @@ static int asus_wmi_add(struct platform_device *pdev)
>  	asus->nv_temp_tgt_available = asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_NV_THERM_TARGET);
>  	asus->panel_overdrive_available = asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_PANEL_OD);
>  	asus->mini_led_mode_available = asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_MINI_LED_MODE);
> +	asus->ally_mcu_usb_switch = acpi_has_method(NULL, ASUS_USB0_PWR_EC0_CSEE)
> +						&& dmi_match(DMI_BOARD_NAME, "RC71L");
>  
>  	err = fan_boost_mode_check_present(asus);
>  	if (err)
> @@ -4654,6 +4665,43 @@ static int asus_hotk_resume(struct device *device)
>  		asus_wmi_fnlock_update(asus);
>  
>  	asus_wmi_tablet_mode_get_state(asus);
> +
> +	return 0;
> +}
> +
> +static int asus_hotk_resume_early(struct device *device)
> +{
> +	struct asus_wmi *asus = dev_get_drvdata(device);
> +
> +	if (asus->ally_mcu_usb_switch) {
> +		if (ACPI_FAILURE(acpi_execute_simple_method(NULL, ASUS_USB0_PWR_EC0_CSEE, 0xB8)))
> +			dev_err(device, "ROG Ally MCU failed to connect USB dev\n");
> +		else
> +			msleep(ASUS_USB0_PWR_EC0_CSEE_WAIT);
> +	}
> +	return 0;
> +}
> +
> +static int asus_hotk_prepare(struct device *device)
> +{
> +	struct asus_wmi *asus = dev_get_drvdata(device);
> +	int result, err;
> +
> +	if (asus->ally_mcu_usb_switch) {
> +		/* When powersave is enabled it causes many issues with resume of USB hub */
> +		result = asus_wmi_get_devstate_simple(asus, ASUS_WMI_DEVID_MCU_POWERSAVE);
> +		if (result == 1) {
> +			dev_warn(device, "MCU powersave enabled, disabling to prevent resume issues");
> +			err = asus_wmi_set_devstate(ASUS_WMI_DEVID_MCU_POWERSAVE, 0, &result);
> +			if (err || result != 1)
> +				dev_err(device, "Failed to set MCU powersave mode: %d\n", err);
> +		}
> +		/* sleep required to ensure USB0 is disabled before sleep continues */
> +		if (ACPI_FAILURE(acpi_execute_simple_method(NULL, ASUS_USB0_PWR_EC0_CSEE, 0xB7)))
> +			dev_err(device, "ROG Ally MCU failed to disconnect USB dev\n");
> +		else
> +			msleep(ASUS_USB0_PWR_EC0_CSEE_WAIT);
> +	}
>  	return 0;
>  }
>  
> @@ -4701,6 +4749,8 @@ static const struct dev_pm_ops asus_pm_ops = {
>  	.thaw = asus_hotk_thaw,
>  	.restore = asus_hotk_restore,
>  	.resume = asus_hotk_resume,
> +	.resume_early = asus_hotk_resume_early,
> +	.prepare = asus_hotk_prepare,
>  };
>  
>  /* Registration ***************************************************************/
> diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
> index 63e630276499..ab1c7deff118 100644
> --- a/include/linux/platform_data/x86/asus-wmi.h
> +++ b/include/linux/platform_data/x86/asus-wmi.h
> @@ -114,6 +114,9 @@
>  /* Charging mode - 1=Barrel, 2=USB */
>  #define ASUS_WMI_DEVID_CHARGE_MODE	0x0012006C
>  
> +/* MCU powersave mode */
> +#define ASUS_WMI_DEVID_MCU_POWERSAVE   0x001200E2
> +
>  /* epu is connected? 1 == true */
>  #define ASUS_WMI_DEVID_EGPU_CONNECTED	0x00090018
>  /* egpu on/off */