Re: [PATCH] platform/x86: Add and use a dual_accel_detect() helper

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On Thu, Jul 29, 2021 at 11:21 AM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> Various 360 degree hinges (yoga) style 2-in-1 devices use 2 accelerometers
> to allow the OS to determine the angle between the display and the base of
> the device.
> On Windows these are read by a special HingeAngleService process which
> calls undocumented ACPI methods, to let the firmware know if the 2-in-1 is
> in tablet- or laptop-mode. The firmware may use this to disable the kbd and
> touchpad to avoid spurious input in tablet-mode as well as to report
> SW_TABLET_MODE info to the OS.
> Since Linux does not call these undocumented methods, the SW_TABLET_MODE
> info reported by various pdx86 drivers is incorrect on these devices.
> Before this commit the intel-hid and thinkpad_acpi code already had 2
> hardcoded checks for ACPI hardware-ids of dual-accel sensors to avoid
> reporting broken info.
> And now we also have a bug-report about the same problem in the intel-vbtn
> code. Since there are at least 3 different ACPI hardware-ids in play, add
> a new dual_accel_detect() helper which checks for all 3, rather then
> adding different hardware-ids to the drivers as bug-reports trickle in.
> Having shared code which checks all known hardware-ids is esp. important
> for the intel-hid and intel-vbtn drivers as these are generic drivers
> which are used on a lot of devices.
> The BOSC0200 hardware-id requires special handling, because often it is
> used for a single-accelerometer setup. Only in a few cases it refers to
> a dual-accel setup, in which case there will be 2 I2cSerialBus resources
> in the device's resource-list, so the helper checks for this.


> +static int dual_accel_i2c_resource_count(struct acpi_resource *ares, void *data)
> +{
> +       struct acpi_resource_i2c_serialbus *sb;
> +       int *count = data;
> +
> +       if (i2c_acpi_get_i2c_resource(ares, &sb))
> +               *count = *count + 1;
> +
> +       return 1;
> +}

It will be a third copy of this in the kernel.
Let's put it to i2c.h or somewhere available for all these users.

> +
> +static int dual_accel_i2c_client_count(struct acpi_device *adev)
> +{
> +       int ret, count = 0;
> +       LIST_HEAD(r);
> +
> +       ret = acpi_dev_get_resources(adev, &r, dual_accel_i2c_resource_count, &count);
> +       if (ret < 0)
> +               return ret;
> +
> +       acpi_dev_free_resource_list(&r);
> +       return count;
> +}

So does this.

Taking into account that this is a bug fix, I'm okay if you do above
as an additional patch (or patches) on top of this.

With Best Regards,
Andy Shevchenko

ibm-acpi-devel mailing list

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