Hi Mark,

On 21 March 2017 at 02:09, Mark Rutland [off-list ref] wrote:

On Tue, Mar 21, 2017 at 01:57:58AM +0800, Fu Wei wrote:

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On 18 March 2017 at 04:01, Mark Rutland [off-list ref] wrote:

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On Tue, Feb 07, 2017 at 02:50:15AM +0800, fu.wei at linaro.org wrote:

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I've not been able to find where the ACPI spec says that zero is not a
valid GSIV. This may simply be an oversight/ambiguity in the spec.

Is there any statement to that effect?

you are right, zero is a  valid GSIV, I will delete this check. Thanks

That being the case, how does one describe a watchdog that does not have
an interrupt?

I think we may can use "Timer Flags", because all the GSIV come with a flag,
if we can define a bit field called "valid" for all GSIV

Bit Field   Bit Offset   Number of bits                 Description
Valid            31                 1                      This bit
indicates the validity of the timer interrupt
                                                                 1:
Interrupt is valid
                                                                 0:
Interrupt is invalid
Then we don't need to test the value of GSIV, just test this bit instead.

Just my thought, hope this makes sense to all of you :-)

As I mentioned, I think this is an oversight/ambiguity in the spec tat
we should address.

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My reading of SBSA is that there is one watchdog in the system.

Is that not the case?

do you mean:
---------------
4.2.4 Watchdogs
The base server system implements a Generic Watchdog as specified in
APPENDIX A: Generic Watchdog.
---------------

I am not sure about that if this is saying "we only have one SBSA
watchdog in a system"

would you let me know where mention it? Do I miss something?

My reading was that the 'a' above meant a single element. i.e.

        The base server system implements _a_ Generic Watchdog as
        specified in APPENDIX A: Generic Watchdog.

Subsequently in 4.2.5, it is stated:

        In this scenario, the system wakeup timer or generic watchdog is
        still required to send its interrupt.

... which only makes sense if there is a single watchdog in the system.

Perhaps this is an oversight in the specification.

Thanks,
Mark.

-- 
Best regards,

Fu Wei
Software Engineer
Red Hat