On Mon, Oct 12, 2020 at 12:50 PM Paul Menzel <pmenzel@xxxxxxxxxxxxx> wrote: > > Dear Rafael, > > > Am 12.10.20 um 12:39 schrieb Rafael J. Wysocki: > > On Sun, Oct 11, 2020 at 1:08 AM Paul Menzel <pmenzel@xxxxxxxxxxxxx> wrote: > >> > >> Dear Dmitry, dear Rafael, dear Len, > >> > >> > >> 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.