Re: [PATCH 2/2] platform/x86/hp: Avoid spurious wakeup on HP ProOne 440

Greg KH
2024-09-05T05:18:18Z

On Thu, Sep 05, 2024 at 12:24:47PM +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. If the touchscreen is present, wait a while to let the USB disconnect
> event fire.
> 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>
> ---
> drivers/platform/x86/hp/hp-wmi.c | 104 ++++++++++++++++++++++++++++++-
> 1 file changed, 103 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c
> index 876e0a97cee1..80fc3ee4deaf 100644
> --- a/drivers/platform/x86/hp/hp-wmi.c
> +++ b/drivers/platform/x86/hp/hp-wmi.c
> @@ -30,6 +30,9 @@
> #include <linux/rfkill.h>
> #include <linux/string.h>
> #include <linux/dmi.h>
> +#include <linux/delay.h>
> +#include <linux/pci.h>
> +#include <linux/usb.h>
>
> MODULE_AUTHOR("Matthew Garrett <mjg59@srcf.ucam.org>");
> MODULE_DESCRIPTION("HP laptop WMI driver");
> @@ -1708,6 +1711,52 @@ static void __exit hp_wmi_bios_remove(struct platform_device *device)
> platform_profile_remove();
> }
>
> +static int hp_wmi_suspend_handler(struct device *device)
> +{
> + acpi_handle handle;
> + struct acpi_device *adev;
> + struct device *physdev;
> + struct usb_port *port_dev;
> + struct usb_device *udev;
> + acpi_status status;
> + bool found = false;
> +
> + /* The USB touchscreen device always connects to HS11 */
> + status = acpi_get_handle(NULL, "\\_SB.PC00.XHCI.RHUB.HS11", &handle);
> + if (ACPI_FAILURE(status))
> + return 0;
> +
> + adev = acpi_fetch_acpi_dev(handle);
> + if (!adev)
> + return 0;
> +
> + physdev = get_device(acpi_get_first_physical_node(adev));
> + if (!physdev)
> + return 0;
> +
> + port_dev = to_usb_port(physdev);

That's a brave cast, how do you "know" this is this device type?

> + if (port_dev->state == USB_STATE_NOTATTACHED)
> + return 0;
> +
> + udev = port_dev->child;
> +
> + if (udev) {
> + usb_get_dev(udev);
> + if (le16_to_cpu(udev->descriptor.idVendor) == 0x1fd2 &&
> + le16_to_cpu(udev->descriptor.idProduct) == 0x8102) {
> + dev_dbg(&hp_wmi_platform_dev->dev, "LG Melfas touchscreen found\n");
> + found = true;
> + }
> + usb_put_dev(udev);
> +
> + /* Let the xhci have time to handle disconnect event */
> + if (found)
> + msleep(200);

why 200?

> + }
> +
> + return 0;
> +}
> +
> static int hp_wmi_resume_handler(struct device *device)
> {
> /*
> @@ -1745,7 +1794,7 @@ 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 +1920,57 @@ 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));

When drivers work properly, they are quiet, was this ment to be
dev_dbg()?

> + else
> + return 1;
> +
> + vga_link = device_link_add(&vga->dev, &hp_wmi_platform_dev->dev,
> + DL_FLAG_STATELESS);
> + if (vga_link)
> + dev_info(&hp_wmi_platform_dev->dev, "Suspend after %s\n",
> + pci_name(vga));

Same here.

thanks,

greg k-h