Re: [PATCH] HID: i2c: Call acpi_device_fix_up_power for ACPI-enumerated devices

[Benjamin Tissoires <benjamin.tissoires@redhat.com>]

Hi Hans,

On May 07 2017 or thereabouts, Hans de Goede wrote:
> ACPI devices which do not have a _PSC method are assumed to have been
> put in D0 by the BIOS, but for touchscreens that is not always true,
> so call acpi_device_fix_up_power to explicitly put devices without a
> _PSC method into D0 state.
> 
> This fixes the SIS0817 i2c-hid touchscreen on a Peaq C1010 2-in-1
> device failing to probe with a "hid_descr_cmd failed" error.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/hid/i2c-hid/i2c-hid.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
> index ea3c3546cef7..c716d9605940 100644
> --- a/drivers/hid/i2c-hid/i2c-hid.c
> +++ b/drivers/hid/i2c-hid/i2c-hid.c
> @@ -960,6 +960,15 @@ static int i2c_hid_acpi_pdata(struct i2c_client *client,
>  	return 0;
>  }
>  
> +static void i2c_hid_acpi_fix_up_power(struct device *dev)
> +{
> +	acpi_handle handle = ACPI_HANDLE(dev);
> +	struct acpi_device *adev;
> +
> +	if (handle && acpi_bus_get_device(handle, &adev) == 0)
> +		acpi_device_fix_up_power(adev);

I am wondering if this is not something that should be handled by
acpi-core or i2c-core. Looks like something pretty generic.

Also, isn't this also needed on resume (or reset_resume)?

Cheers,
Benjamin

> +}
> +
>  static const struct acpi_device_id i2c_hid_acpi_match[] = {
>  	{"ACPI0C50", 0 },
>  	{"PNP0C50", 0 },
> @@ -972,6 +981,8 @@ static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
>  {
>  	return -ENODEV;
>  }
> +
> +static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {}
>  #endif
>  
>  #ifdef CONFIG_OF
> @@ -1070,6 +1081,8 @@ static int i2c_hid_probe(struct i2c_client *client,
>  	if (ret < 0)
>  		goto err;
>  
> +	i2c_hid_acpi_fix_up_power(&client->dev);
> +
>  	pm_runtime_get_noresume(&client->dev);
>  	pm_runtime_set_active(&client->dev);
>  	pm_runtime_enable(&client->dev);
> -- 
> 2.12.2
>