Re: [PATCH 4/5] platform/x86: intel-vbtn: Also handle tablet-mode switch on "Detachable" and "Portable" chassis-types

[Hans de Goede]

Hi,

On 5/4/20 5:37 PM, Mario.Limonciello@xxxxxxxx wrote:
> > -----Original Message-----
> > From: Hans de Goede <hdegoede@xxxxxxxxxx>
> > Sent: Saturday, May 2, 2020 1:30 PM
> > To: Darren Hart; Andy Shevchenko; Limonciello, Mario
> > Cc: Hans de Goede; linux-acpi@xxxxxxxxxxxxxxx; platform-driver-
> > x86@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> > Subject: [PATCH 4/5] platform/x86: intel-vbtn: Also handle tablet-mode switch
> > on "Detachable" and "Portable" chassis-types
> >
> >
> > [EXTERNAL EMAIL]
> >
> > Commit de9647efeaa9 ("platform/x86: intel-vbtn: Only activate tablet mode
> > switch on 2-in-1's") added a DMI chassis-type check to avoid accidentally
> > reporting SW_TABLET_MODE = 1 to userspace on laptops.
> >
> > Some devices with a detachable keyboard and using the intel-vbnt (INT33D6)
> > interface to report if they are in tablet mode (keyboard detached) or not,
> > report 32 / "Detachable" as chassis-type, e.g. the HP Pavilion X2 series.
> >
> > Other devices with a detachable keyboard and using the intel-vbnt (INT33D6)
> > interface to report SW_TABLET_MODE, report 8 / "Portable" as chassis-type.
> > The Dell Venue 11 Pro 7130 is an example of this.
> >
> > Extend the DMI chassis-type check to also accept Portables and Detachables
> > so that the intel-vbtn driver will report SW_TABLET_MODE on these devices.
> >
> > Note the chassis-type check was originally added to avoid a false-positive
> > tablet-mode report on the Dell XPS 9360 laptop. To the best of my knowledge
> > that laptop is using a chassis-type of 9 / "Laptop", so after this commit
> > we still ignore the tablet-switch for that chassis-type.
>
> Yes that's correct.
>
> > Fixes: de9647efeaa9 ("platform/x86: intel-vbtn: Only activate tablet mode
> > switch on 2-in-1's")
> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> > ---
> > Looking at the Microsoft Windows documentation for tablet-mode reporting:
> > https://docs.microsoft.com/en-us/windows-hardware/drivers/gpiobtn/button-
> > implementation
> >
> > Then the presence of a tablet-mode switch is indicated by the presence
> > of a PNP0C60 compatible ACPI devices. There are 2 ways in which this device
> > can report the tablet-mode. 1. Directly providing a GpioInt resource inside
> > the PNP0C60 device, 2. Through injecting events from a Windows driver.
> >
> > It seems that the intel-vbtn / the INT33D6 ACPI device is the ACPI side
> > of Intel's generic solution for the case where the tablet-mode comes from
> > the embedded-controller and needs to be "injected".
> >
> > This all suggests that it might be better to replace the chassis-type
> > check with a acpi_dev_present("PNP0C60", NULL, -1) check.
> >
> > Mario, can you provide an acpidump and alsa-info.sh output for the
> > Dell XPS 9360, so that I can check if that might help with the issue
> > there, and thus is a potential candidate to replace the chassis-type
> > check?
>
> Unfortunately with WFH right now, I don't have access to a XPS 9630 to
> double check the patch series.
>
> However I do agree this should be a good approach.

Ok, so lets stick with the chassis-type check (as amended by this patch)
for now then. Then once you are able to go to your office again, we
can examine the acpi_dev_present("PNP0C60", NULL, -1) alternative.

> Reviewed-by: Mario Limonciello <Mario.limonciello@xxxxxxxx>

Thank you.

Regards,

Hans




> > ---
> >   drivers/platform/x86/intel-vbtn.c | 12 +++++++++++-
> >   1 file changed, 11 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/platform/x86/intel-vbtn.c b/drivers/platform/x86/intel-
> > vbtn.c
> > index 500fae82e12c..4921fc15dc6c 100644
> > --- a/drivers/platform/x86/intel-vbtn.c
> > +++ b/drivers/platform/x86/intel-vbtn.c
> > @@ -158,12 +158,22 @@ static void detect_tablet_mode(struct platform_device
> > *device)
> >   static bool intel_vbtn_has_switches(acpi_handle handle)
> >   {
> >   	const char *chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
> > +	unsigned long chassis_type_int;
> >   	unsigned long long vgbs;
> >   	acpi_status status;
> >
> > -	if (!(chassis_type && strcmp(chassis_type, "31") == 0))
> > +	if (kstrtoul(chassis_type, 10, &chassis_type_int))
> >   		return false;
> >
> > +	switch (chassis_type_int) {
> > +	case  8: /* Portable */
> > +	case 31: /* Convertible */
> > +	case 32: /* Detachable */
> > +		break;
> > +	default:
> > +		return false;
> > +	}
> > +
> >   	status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
> >   	return ACPI_SUCCESS(status);
> >   }
> > --
> > 2.26.0