Re: [Xen-devel] [PATCH 3/3 v3] xen: Fix 16550 UART console for HP Moonshot (Aarch64) platform

[Julien Grall <julien.grall@xxxxxxxxxx>]

+ Graeme

On 27/11/17 10:06, Jan Beulich wrote:
> > > > On 24.11.17 at 12:39, <bhupinder.thakur@xxxxxxxxxx> wrote:
> > --- a/xen/drivers/char/ns16550.c
> > +++ b/xen/drivers/char/ns16550.c
> > @@ -1571,6 +1571,30 @@ DT_DEVICE_END
> >   #endif /* HAS_DEVICE_TREE */
> >   
> >   #if defined(CONFIG_ACPI) && defined(CONFIG_ARM)
> > +/*
> > + * APM X-Gene v1 and v2 UART hardware is an 16550 like device but has its
> > + * register aligned to 32-bit. In addition, the BIOS also encoded the
> > + * access width to be 8 bits. This function detects this errata condition.
> > + */
> > +static bool xgene_8250_erratum_present(struct acpi_table_spcr *tb)
> Is this really to be considered an erratum? From the description it
> doesn't sound like this couldn't have been a deliberate decision.
> IOW - does their behavior contradict any spec? (ACPI not providing
> information in field and access width looks suspicious too - GAS fields
> exist for both.)
I believe the problem here is the firmware table does not describe 
correctly the hardware. I have CCed Graeme which might be able to confirm.
Cheers,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel