Re: [PATCH] Add support for 64-bit AHCI BAR.

2015-01-08 21:40 GMT+01:00 Konstantin Belousov <kostikbel_at_gmail.com>:

> > However, if
> > AHCI uses 64-bit base addresses, then this register consists of two
> dwords
> > starting at offset 0x20 - BAR4 and BAR5. This is the case on our arm64
> > target and possibly other platforms using 64-bit BARs for AHCI.
> Is it specified anywhere, or just a quirk of the specific implementation ?
> If it is a quirk, would it make sense to also check the vendor or device
> id before applying the logic ?
>
>
Yes, indeed it is a quirk as I just found out that our platform vendor
actually uses BAR(0) as AHCI ABAR, while BAR(4) is used for something else.
I found it implemented as a quirk in Linux AHCI code.
The BAR is still 64-bit but in a different position than AHCI spec stated.
I changed it as you suggested, the new patch is in the attachment. Please
take a look.

>
> > The following patch adds a check for the extended BAR in
> ahci_pci_attach()
> > and sets the 'rid' in bus_alloc_resource_any accordingly. It fixes the
> > allocation error on our platform.
> >
> > Please review and test this patch on other platforms. If there are no
> > issues then it will be committed in a week.
> >
>