Re: i8042_init: PS/2 mouse not detected with ACPIPnP/PnPBIOS

[Paul Menzel]

Dear Rafael, dear Dmitry,


Am 12.10.20 um 13:00 schrieb Rafael J. Wysocki:
> On Mon, Oct 12, 2020 at 12:50 PM Paul Menzel wrote:

> > Am 12.10.20 um 12:39 schrieb Rafael J. Wysocki:
> > > On Sun, Oct 11, 2020 at 1:08 AM Paul Menzel wrote:

> > > > Am 08.10.20 um 00:16 schrieb Dmitry Torokhov:
> > > >
> > > > > On Wed, Oct 07, 2020 at 11:18:41PM +0200, Paul Menzel wrote:
> > > >
> > > > > > On the Asus F2A85-M PRO Linux 5.9-rc8 (and previous versions) does not
> > > > > > recognize a plugged in PS/2 mouse using the Plug & Play method. The PS/2
> > > > > > keyboard is detected fine, and using `i8042.nopnp`, the PS/2 mouse also
> > > > > > works.
> > > > > >
> > > > > > > [    1.035915] calling  i8042_init+0x0/0x42d @ 1
> > > > > > > [    1.035947] i8042: PNP: PS/2 Controller [PNP0303:PS2K] at 0x60,0x64 irq 1
> > > > > > > [    1.035948] i8042: PNP: PS/2 appears to have AUX port disabled, if this is incorrect please boot with i8042.nopnp
> > > > > > > [    1.036589] serio: i8042 KBD port at 0x60,0x64 irq 1
> > > > > > > [    1.036621] initcall i8042_init+0x0/0x42d returned 0 after 687 usecs
> > > > > >
> > > > > > But, the DSDT includes the “mouse device”. From
> > > > > >
> > > > > >        acpidump > dump.bin; acpixtract dump.bin; iasl -d *dat; more dsdt.dsl
> > > > > >
> > > > > > we get
> > > > > >
> > > > > >                    Device (PS2M)
> > > > > >                    {
> > > > > >                        Name (_HID, EisaId ("PNP0F03") /* Microsoft PS/2-style Mouse */)  // _HID: Hardware ID
> > > > > >                        Name (_CID, EisaId ("PNP0F13") /* PS/2 Mouse */) // _CID: Compatible ID
> > > > > >                        Method (_STA, 0, NotSerialized)  // _STA: Status
> > > > > >                        {
> > > > > >                            If ((IOST & 0x4000))
> > > > > >                            {
> > > > > >                                Return (0x0F)
> > > > > >                            }
> > > > > >                            Else
> > > > > >                            {
> > > > > >                                Return (Zero)
> > > > > >                            }
> > > > > >                        }
> > > > > >
> > > > > > and the identifiers PNP0F03 and PNP0F13 are both listed in the array
> > > > > > `pnp_aux_devids[]`. But adding print statements to `i8042_pnp_aux_probe()`,
> > > > > > I do not see them, so the function does not seem to be called.
> > > > >
> > > > > My guess is that _STA returns 0 indicating that the device is not
> > > > > present. I would try tracking where IOST is being set and figuring out
> > > > > why it does not have mouse bit enabled.
> > > >
> > > > Does the ACPI subsystem allow to track, how ACPI variables(?) like IOST
> > > > are read and set?
> > >
> > > My guess would be that IOST is a field in an operation region which
> > > would indicate that it is initialized by the bootstrap part of the
> > > BIOS.
> >
> > Thank you for your answer. But how can I verify that?
>
> Inspecting the ACPI tables from the system in question could help you
> to find out whether or not IOST really is a field in an operation
> region, but its initial value may not be possible to determine this
> way.
>
> > Is there a Linux kernel parameter, that would print it?
>
> Not that I know of.

I created an issue in the Linux kernel bugtracker [1] and attached the 
output of `acpidump` there.

Could

    If ((IOST & 0x4000))

versus

    If ((IOST & 0x0400))

be a typo?


Kind regards,

Paul


[1]: https://bugzilla.kernel.org/show_bug.cgi?id=209657