Re: ITE8708 on ASUS PN50 uses a 16 byte io region

[Sean Young <sean@mess.org>]

On Sat, Sep 26, 2020 at 10:22:46AM +0200, Michael Zimmermann wrote:
> Hi,
> 
> here's the resource descriptor from my DSDT:
> Name (BUF0, ResourceTemplate ()
> {
>     IO (Decode16,
>         0x0000,             // Range Minimum
>         0x0000,             // Range Maximum
>         0x01,               // Alignment
>         0x10,               // Length
>         _Y1A)
>     IRQNoFlags (_Y1B)
>         {}
>     DMA (Compatibility, NotBusMaster, Transfer8, )
>         {}
> })
> 
> As you can see it uses 16 bytes for the IO region while the driver
> drivers/media/rc/ite-cir.c expects 8.
> I don't see any obvious reason why they do that since they only seem
> to write two words in there, and if I edit the DSDT to change the
> length from 0x10 to 0x8 the linux driver detects the device properly
> it works just fine.
> 
> So is this a bug on ASUS' side or should we just accept longer regions
> for the same device type?

So looking at the driver, some devices do have an io region of 16 and
others expect 8. See the io_region_size field of ite_dev_descs.

So for ITE8708 the io_region_size is set to 8. Does your device really
have an ITE8708 or is the DSDT wrong? 


Sean