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

[Rafael J. Wysocki]

On 10/13/2020 5:00 PM, Paul Menzel wrote:
> 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?
Yes, it could.