Hi Guenter,


On 4 June 2015 at 02:25, Guenter Roeck [off-list ref] wrote:

On Wed, Jun 03, 2015 at 01:16:41PM -0500, Timur Tabi wrote:

quoted

On 06/01/2015 11:05 PM, fu.wei@linaro.org wrote:

quoted

+    if (wdd->pretimeout)
+            /* The pretimeout is valid, go panic */
+            panic("SBSA Watchdog pre-timeout");

The problem with this is that WS1 will still occur.  So a few seconds after
the panic() call, the hardware will reset.  There won't be any time to debug
or log anything.

In general the idea here would be to use a crashdump kernel, which,
when loaded, would reset the watchdog before it fires. This kernel
would then write a core dump to a specified location.

If arm64 doesn't support a crashdump kernel, it might still be possible
to log the backtrace somewhere (eg in nvram using pstore if that is
supported via acpi or efi).

yes, you are right , thanks for explaining this.

Is there reason to believe that this all won't work on arm64 ?

I don't think there is a reason.

Thanks,
Guenter

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Fu Wei
Software Engineer
Red Hat Software (Beijing) Co.,Ltd.Shanghai Branch
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