Re: ACPI defined devices not showing up under /sys/bus/platform/devices

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Thu, Sep 18, 2014 at 06:02:40PM -0300, Marcos Paulo de souza wrote:
> Hi,
> 
> On 09/18/2014 05:49 PM, Hans de Goede wrote:
> >Hi,
> >
> >On 09/18/2014 04:01 PM, Mika Westerberg wrote:
> >>On Thu, Sep 18, 2014 at 02:04:11PM +0200, Hans de Goede wrote:
> >>>Hi,
> >>>
> >>>I'm trying to help various users with Asus X450 and Asus X550 laptops
> >>>to get their touchpad to work:
> >>>
> >>>https://bugzilla.redhat.com/show_bug.cgi?id=1110011
> >>>
> >>>We believe that this touchpad is connected over i2c, using the
> >>>i2c-designware-platform driver.
> >>>
> >>>If you look at the DSDT attached there you can clearly see
> >>>nodes defines which should lead to e.g. :
> >>>
> >>>/sys/bus/platform/devices/INT33C2:00
> >>>
> >>>Showing up (which should then be bound by i2c-designware-platform).
> >>>
> >>>But nothing is showing up, not a single ACPI defined device shows
> >>>up actually:
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>[root@asusx550 devices]# ll
> >>>insgesamt 0
> >>>lrwxrwxrwx. 1 root root 0 22. Jul 14:56 alarmtimer -> ../../../devices/platform/alarmtimer
> >>>lrwxrwxrwx. 1 root root 0 25. Jul 23:54 asus-nb-wmi -> ../../../devices/platform/asus-nb-wmi
> >>>lrwxrwxrwx. 1 root root 0 25. Jul 23:54 coretemp.0 -> ../../../devices/platform/coretemp.0
> >>>lrwxrwxrwx. 1 root root 0 22. Jul 14:56 efi-framebuffer.0 -> ../../../devices/platform/efi-framebuffer.0
> >>>lrwxrwxrwx. 1 root root 0 22. Jul 14:56 Fixed MDIO bus.0 -> ../../../devices/platform/Fixed MDIO bus.0
> >>>lrwxrwxrwx. 1 root root 0 22. Jul 14:56 i8042 -> ../../../devices/platform/i8042
> >>>lrwxrwxrwx. 1 root root 0 25. Jul 23:54 iTCO_wdt -> ../../../devices/pci0000:00/0000:00:1f.0/iTCO_wdt
> >>>lrwxrwxrwx. 1 root root 0 25. Jul 23:54 microcode -> ../../../devices/platform/microcode
> >>>lrwxrwxrwx. 1 root root 0 22. Jul 14:56 pcspkr -> ../../../devices/platform/pcspkr
> >>>lrwxrwxrwx. 1 root root 0 25. Jul 23:54 regulatory.0 -> ../../../devices/platform/regulatory.0
> >>>lrwxrwxrwx. 1 root root 0 25. Jul 23:54 rtsx_pci_ms.0 -> ../../../devices/pci0000:00/0000:00:1c.2/0000:02:00.0/rtsx_pci_ms.0
> >>>lrwxrwxrwx. 1 root root 0 25. Jul 23:54 rtsx_pci_sdmmc.0 -> ../../../devices/pci0000:00/0000:00:1c.2/0000:02:00.0/rtsx_pci_sdmmc.0
> >>>lrwxrwxrwx. 1 root root 0 22. Jul 14:56 serial8250 -> ../../../devices/platform/serial8250
> >>>
> >>>
> >>>Which is weird, since any recent machine usually has at least one or 2
> >>>show up.
> >>It depends whether the BIOS has enabled those or not.
> >>
> >>If
> >>
> >>  # cat /sys/bus/acpi/devices/INT33C2:00/status
> >>  # cat /sys/bus/acpi/devices/INT33C3:00/status
> >>
> >>returns 0xf, then the device should be there, otherwise it is not.
> >Interesting. Marcos, can you give this a try please ?
> Hans, both here returned 0. As I said to you, I'm using Fedora in insecure
> mode (I don't know if this changes anything).

That just means that your BIOS has disabled these devices. Unless there
is a menu somewhere in BIOS setup to enable these, there is nothing we
can do in the kernel to make them appear.

> >>The "status" refers directly shat _STA() ACPI method returns.
> >Ok, so assuming that Marcos' testing shows it is not enabled,
> >is there anything we can, could there be some ACPI call to
> >enable these devs ?
> >
> >>Note that the device could also be in PCI mode, in case lspci should
> >>show it.
> >Right, it does not show in lspci.

OK. So I think that this particular machine, either does not have Intel
LPSS (it is not Haswell-LP) or the devices have been deliberately
disabled for some reason.