Re: [PATCH v2] platform/x86/hp: Avoid spurious wakeup on HP ProOne 440

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Sep 06, 2024 at 11:03:00AM +0800, Kai-Heng Feng wrote:
> The HP ProOne 440 has a power saving design that when the display is
> off, it also cuts the USB touchscreen device's power off.
> 
> This can cause system early wakeup because cutting the power off the
> touchscreen device creates a disconnect event and prevent the system
> from suspending:
> [  445.814574] hub 2-0:1.0: hub_suspend
> [  445.814652] usb usb2: bus suspend, wakeup 0
> [  445.824629] xhci_hcd 0000:00:14.0: Port change event, 1-11, id 11, portsc: 0x202a0
> [  445.824639] xhci_hcd 0000:00:14.0: resume root hub
> [  445.824651] xhci_hcd 0000:00:14.0: handle_port_status: starting usb1 port polling.
> [  445.844039] xhci_hcd 0000:00:14.0: PM: pci_pm_suspend(): hcd_pci_suspend+0x0/0x20 returns -16
> [  445.844058] xhci_hcd 0000:00:14.0: PM: dpm_run_callback(): pci_pm_suspend+0x0/0x1c0 returns -16
> [  445.844072] xhci_hcd 0000:00:14.0: PM: failed to suspend async: error -16
> [  446.276101] PM: Some devices failed to suspend, or early wake event detected
> 
> So add a quirk to make sure the following is happening:
> 1. Let the i915 driver suspend first, to ensure the display is off so
>    system also cuts the USB touchscreen's power.
> 2. Wait a while to let the USB disconnect event fire and get handled.
> 3. Since the disconnect event already happened, the xhci's suspend
>    routine won't be interrupted anymore.
> 
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
> v2:
>  - Remove the part that searching for the touchscreen device.
>  - Wording.
> 
>  drivers/platform/x86/hp/hp-wmi.c | 59 +++++++++++++++++++++++++++++++-
>  1 file changed, 58 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c
> index 876e0a97cee1..7c239d8d02fd 100644
> --- a/drivers/platform/x86/hp/hp-wmi.c
> +++ b/drivers/platform/x86/hp/hp-wmi.c
> @@ -30,6 +30,8 @@
>  #include <linux/rfkill.h>
>  #include <linux/string.h>
>  #include <linux/dmi.h>
> +#include <linux/delay.h>
> +#include <linux/pci.h>
>  
>  MODULE_AUTHOR("Matthew Garrett <mjg59@srcf.ucam.org>");
>  MODULE_DESCRIPTION("HP laptop WMI driver");
> @@ -1708,6 +1710,14 @@ static void __exit hp_wmi_bios_remove(struct platform_device *device)
>  		platform_profile_remove();
>  }
>  
> +static int hp_wmi_suspend_handler(struct device *device)
> +{
> +	/* Let the xhci have time to handle disconnect event */
> +	msleep(200);
> +
> +	return 0;
> +}
> +
>  static int hp_wmi_resume_handler(struct device *device)
>  {
>  	/*
> @@ -1745,7 +1755,7 @@ static int hp_wmi_resume_handler(struct device *device)
>  	return 0;
>  }
>  
> -static const struct dev_pm_ops hp_wmi_pm_ops = {
> +static struct dev_pm_ops hp_wmi_pm_ops = {
>  	.resume  = hp_wmi_resume_handler,
>  	.restore  = hp_wmi_resume_handler,
>  };
> @@ -1871,6 +1881,51 @@ static int hp_wmi_hwmon_init(void)
>  	return 0;
>  }
>  
> +static int lg_usb_touchscreen_quirk(const struct dmi_system_id *id)
> +{
> +	struct pci_dev *vga, *xhci;
> +	struct device_link *vga_link, *xhci_link;
> +
> +	vga = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
> +
> +	xhci = pci_get_class(PCI_CLASS_SERIAL_USB_XHCI, NULL);
> +
> +	if (vga && xhci) {
> +		xhci_link = device_link_add(&hp_wmi_platform_dev->dev, &xhci->dev,
> +				      DL_FLAG_STATELESS);
> +		if (xhci_link)
> +			dev_info(&hp_wmi_platform_dev->dev, "Suspend before %s\n",
> +				 pci_name(xhci));

Again, please turn these into dev_dbg() calls.

thanks,

greg k-h