Re: [PATCH] [v1] coresight: funnel: inport schedule by priority can not take work

[Chao Xu]

在 2026/10/27 16:41, Leo Yan 写道:

> Hi,
>
> On Sun, Oct 25, 2026 at 09:13:07PM +0800, Chao Xu wrote:
> > Before enable funnel, priority must be set. Changing the port
> > priorities in real time is not supported.
> > If the priority control register is written when one or more of ports
> > are enable, then the write is silently rejected.
> Could you cite the relevant documentation in commit log?
>
>    The CoreSight SoC-600 TRM, section 9.11.2, PRIORITYCONTROL, a funnel
>    rejects priority register writes whenever any port is enabled. The
>    current sequence therefore prevent the configured priorities from
>    taking effect.
>
>    Write the priority register before enabling the first port.
v2 patch add.
> > Signed-off-by: Chao Xu <xuchao066@xxxxxxx>
> > ---
> >   drivers/hwtracing/coresight/coresight-funnel.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
> > index af40814ce560..17f985798d7f 100644
> > --- a/drivers/hwtracing/coresight/coresight-funnel.c
> > +++ b/drivers/hwtracing/coresight/coresight-funnel.c
> > @@ -66,8 +66,8 @@ static int dynamic_funnel_enable_hw(struct funnel_drvdata *drvdata, int port)
> >   	functl &= ~FUNNEL_HOLDTIME_MASK;
> >   	functl |= FUNNEL_HOLDTIME;
> >   	functl |= (1 << port);
> > -	writel_relaxed(functl, drvdata->base + FUNNEL_FUNCTL);
> >   	writel_relaxed(drvdata->priority, drvdata->base + FUNNEL_PRICTL);
> > +	writel_relaxed(functl, drvdata->base + FUNNEL_FUNCTL);
> Please move the priority write into the first port branch:
>
>    /* Claim the device only when we enable the first slave */
>    if (!(functl & FUNNEL_ENSx_MASK)) {
>            rc = coresight_claim_device_unlocked(csdev);
>            if (rc)
>                    goto done;
>
>            /* Update priorities while all ports are disabled */
>            writel_relaxed(drvdata->priority,
>                           drvdata->base + FUNNEL_PRICTL);
>    }
here is more better then v1 patch, v2 patch will be sent.
> Thanks,
> Leo