Re: [PATCH 1/1] x86/acpi: Use FADT flags to determine the PMTMR width

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Tue, Jun 16, 2020 at 05:11:58PM +0200, Jan Beulich wrote:
> On 16.06.2020 16:59, Roger Pau Monné wrote:
> > On Tue, Jun 16, 2020 at 03:25:42PM +0200, Jan Beulich wrote:
> >> --- unstable.orig/xen/arch/x86/acpi/boot.c
> >> +++ unstable/xen/arch/x86/acpi/boot.c
> >> @@ -480,7 +480,9 @@ static int __init acpi_parse_fadt(struct
> >>    if (fadt->header.revision >= FADT2_REVISION_ID) {
> >>            /* FADT rev. 2 */
> >>            if (fadt->xpm_timer_block.space_id ==
> >> -              ACPI_ADR_SPACE_SYSTEM_IO) {
> >> +              ACPI_ADR_SPACE_SYSTEM_IO &&
> >> +              (fadt->xpm_timer_block.access_width == 0 ||
> >> +               fadt->xpm_timer_block.access_width == 3)) {
> > 
> > We should really have defines for those values, or else they seem to
> > imply actual access sizes. What about adding
> > ACPI_ADDR_ACCESS_{LEGACY,BYTE,WORD,DWORD,QWORD}?
> 
> If there were such defines, I'd have used them. Adding them is
> inappropriate though, as this would modify an imported header in a
> Xen-specific way. We could leverage ACPI_ACCESS_BIT_WIDTH() here,
> though.

Yes, that would be better IMO.

Thanks, Roger.