Re: Possible regression due to "tick: broadcast: Prevent livelock from event handler"

From: Magnus Damm
Date: Mon Jul 06 2015 - 00:45:29 EST


Hi Geert,

On Sat, Jul 4, 2015 at 2:02 AM, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> Hi Wolfram,
>
> On Fri, Jul 3, 2015 at 4:37 PM, Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote:
>>> So this is a single core machine and uses the em_sti timer w/o the
>>> broadcast nonsense. In Simons case it looks like em_sti is used as
>>> broadcast device.
>>
>> We use the same board. Just my kernel has SMP=n.
>
> Unlike our other multi-core A9 SoCs, emev2.dtsi doesn't have a node
> for the arm,cortex-a9-twd-timer?

That's right, the TWD was never enabled on upstream EMEV2. I believe
it is documented in the data sheet though, however the actual
vendor-specific glue is a bit different compared to other SoCs from
Renesas Electronics - this most likely since EMEV2 was initially made
by NEC Electronics instead of Renesas. I've been told that it was one
of the earlier Cortex-A9 designs around so some special surprises may
exist!

Cheers,

/ magnus
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