Re: [Xen-devel] [PATCH] xen/arm: remove check for generic timer support for arm64

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Mon, 2014-06-02 at 15:50 +0100, Julien Grall wrote:
> On 06/02/2014 03:48 PM, Ian Campbell wrote:
> > On Mon, 2014-06-02 at 14:07 +0530, vijay.kilari@xxxxxxxxx wrote:
> >> From: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx>
> >>
> >> arm64 always supports generic timer. So check is not required
> >> for arm64. For platforms which supports only aarch64 mode this
> >> check always passes and panics
> >>
> >> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx>
> >> ---
> >>  xen/arch/arm/time.c |    2 ++
> >>  1 file changed, 2 insertions(+)
> >>
> >> diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
> >> index 4c3e1a6..801c130 100644
> >> --- a/xen/arch/arm/time.c
> >> +++ b/xen/arch/arm/time.c
> >> @@ -138,8 +138,10 @@ int __init init_xen_time(void)
> >>          panic("Timer: Cannot initialize platform timer");
> >>  
> >>      /* Check that this CPU supports the Generic Timer interface */
> >> +#ifdef CONFIG_ARM_32
> >>      if ( !cpu_has_gentimer )
> >>          panic("CPU does not support the Generic Timer v1 interface");
> >> +#endif
> > 
> > Coming at this form a different angle (ignoring feature flags etc), we
> > have by this point already been told by the device tree that a generic
> > timer is present (we panic if we don't find a node). So this check is a
> > bit redundant (I suppose it would catch people with an incorrect DT, but
> > I expect we'd figure that out pretty soon even without this check).
> > 
> > Perhaps we should just remove this check altogether? Or the suggestion
> > to #define it to 1 on arm64 would also work.
> 
> I though about removing this bit... but I'm not sure if ACPI will give
> us the necessary information for the generic timer.

It had better, since we need it to operate...



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel