On Tue, Sep 8, 2020 at 8:20 PM Maximilian Luz <luzmaximilian@xxxxxxxxx> wrote:
>
> Conventionally, wake-up events for a specific device, in our case the
> lid device, are managed via the ACPI _PRW field. While this does not
> seem strictly necessary based on ACPI spec, the kernel disables GPE
> wakeups to avoid non-wakeup interrupts preventing suspend by default and
> only enables GPEs associated via the _PRW field with a wake-up capable
> device. This behavior has been introduced in commit f941d3e41da7 ("ACPI:
> EC / PM: Disable non-wakeup GPEs for suspend-to-idle") and is described
> in more detail in its commit message.
>
> Unfortunately, on MS Surface devices, there is no _PRW field present on
> the lid device, thus no GPE is associated with it, and therefore the GPE
> responsible for sending the status-change notification to the lid gets
> disabled during suspend, making it impossible to wake the device via the
> lid.
>
> This patch introduces a pseudo-device and respective driver which, based
> on some DMI matching, marks the corresponding GPE of the lid device for
> wake and enables it during suspend. The behavior of this driver models
> the behavior of the ACPI/PM core for normal wakeup GPEs, properly
> declared via the _PRW field.
...
> +#include <linux/platform_device.h>
> +
> +
One blank line is enough.
...
> + .gpe_number = 0x17,
> + .gpe_number = 0x4D,
> + .gpe_number = 0x4F,
> + .gpe_number = 0x57,
>From where these numbers come from? Can we get them from firmware (ACPI)?
...
> + { }
> +};
> +
> +
One is enough. Same for other places.
...
> +static int surface_gpe_suspend(struct device *dev)
> +{
> + const struct surface_lid_device *lid;
> +
> + lid = dev_get_platdata(dev);
There is enough room to put this assignment directly into definition.
> + return surface_lid_enable_wakeup(dev, lid, true);
> +}
> +
> +static int surface_gpe_resume(struct device *dev)
> +{
> + const struct surface_lid_device *lid;
> +
> + lid = dev_get_platdata(dev);
Ditto.
> + return surface_lid_enable_wakeup(dev, lid, false);
> +}
...
> +static int surface_gpe_probe(struct platform_device *pdev)
> +{
> + const struct surface_lid_device *lid;
> + int status;
> +
> + lid = dev_get_platdata(&pdev->dev);
> + if (!lid)
> + return -ENODEV;
Can we use software nodes?
> + status = acpi_mark_gpe_for_wake(NULL, lid->gpe_number);
> + if (status) {
> + dev_err(&pdev->dev, "failed to mark GPE for wake: %d\n", status);
> + return -EINVAL;
> + }
> +
> + status = acpi_enable_gpe(NULL, lid->gpe_number);
Did I miss anything or all calls of enable / disable GPE are using
NULL as a first parameter? What the point in such case?
> + if (status) {
> + dev_err(&pdev->dev, "failed to enable GPE: %d\n", status);
> + return -EINVAL;
> + }
> +
> + status = surface_lid_enable_wakeup(&pdev->dev, lid, false);
> + if (status) {
> + acpi_disable_gpe(NULL, lid->gpe_number);
> + return status;
> + }
> +
> + return 0;
> +}
...
> +static void __exit surface_gpe_exit(void)
> +{
> + if (!surface_gpe_device)
> + return;
This is redundant check.
> + platform_device_unregister(surface_gpe_device);
> + platform_driver_unregister(&surface_gpe_driver);
> +}
> +
> +module_init(surface_gpe_init);
> +module_exit(surface_gpe_exit);
Attach each to the corresponding method w/o blank line in between.
...
> +MODULE_ALIAS("dmi:*:svnMicrosoftCorporation:pnSurfacePro:*");
> +MODULE_ALIAS("dmi:*:svnMicrosoftCorporation:pnSurfacePro4:*");
Can simply
MODULE_ALIAS("dmi:*:svnMicrosoftCorporation:pnSurface*:*");
work?
--
With Best Regards,
Andy Shevchenko
