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

[Hans de Goede <hdegoede@redhat.com>]

Hi Mika,

First of all many thanks for your input on this.

On 09/19/2014 02:01 PM, Mika Westerberg wrote:
> On Fri, Sep 19, 2014 at 08:48:49AM -0300, Marcos Paulo de souza wrote:
>> Hi,
>>
>> On 09/19/2014 05:47 AM, Mika Westerberg wrote:
>>> 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.
>> Interesting. This machine came with Windows 8, and removed. The touchpad was
>> working on Windows. Mika, I verified my BIOS configurations and there isn't
>> any configuration to enable PCI devices. Do you beleive there is something
>> about secure boot? As it worked with Windows, hwo can it be detected on
>> Linux?
> 
> Are you sure that your touch pad is connected to I2C bus in the first
> place?

No, that is a guess because the windows drivers for this touchpad
can do both ps/2 and i2c-hid, and we're sort of hoping that i2c-hid is
attached, so that we don't need to reverse-engineer a new ps/2 protocol.

But it looks like we are out of luck there, and we really need to figure
out the ps/2 protocol.

> In your ACPI DSDT, there is also a device called PS2M that happens to to
> look like touch pad to me. For example it reports one of these _HIDs:
> 
>                     Method (_HID, 0, NotSerialized)  // _HID: Hardware ID
>                     {
>                         If (SYNA)
>                         {   
>                             Return (0x190A2E4F)
>                         }
> 
>                         If (ALPS)
>                         {   
>                             Return (0x0713A906)
>                         }
> 
>                         If (ELAN)
>                         {   
>                             Return (0x08018416)
>                         }
> 
>                         If (STLC)
>                         {   
>                             Return (0x41C18C4E)
>                         }
> 
>                         If (FOLT)
>                         {
>                             Return (0x01019419)
>                         }

FOLT probably stands for Focaltech, and I bet this is the one which will show up in
/sys/bus/acpi/devices/

If it does show up, is there any way to see how it is supposed to be connected ?

Regards,

Hans