[PATCH v5 04/12] coresight: etm4x: exclude ss_status from drvdata->config

Yeoreum Yun yeoreum.yun at arm.com
Tue Apr 21 03:30:02 PDT 2026


> Hi Mike,
>
> > Hi,
> >
> > This register [bit 31] indicates if a single shot comparator has matched. So
> > read-back provides information to the user post run to determine which if
> > any of the comparators set in this way has actually matched.
>
> Okay. so after disable sysfs session, to check former session
> check whether comprator has matched.
>
> >
> > Moreover, the specification states "Software must reset this bit to 0 to
> > re-enable single-shot control" and "Reset state is unknown. STATUS must be
> > written to set an initial state...."
> >
> > Therefore this register must be written as part of any configuration so
> > should be available in the drvdata->config for both read and write,
>
> But I don't think this is the reason for locate ss_status into "config"
> since its write purpose is not to configure but the "clear" former bit.
> That's why I think it's enough to clear when the new sysfs session starts.
>

IOW, I think it's better to remove ss_status from configfs item
and
  - add field ss_cmp in etm4_cpas
  - add another field ss_status under "etm4_drvdata" to show "PENDING
    and STATUS" bits to sysfs after finishing session.

Is is valid for you?

> --
> Sincerely,
> Yeoreum Yun
>

--
Sincerely,
Yeoreum Yun



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