Re: [PATCH 3/6] coresight: Introduce support for Coresight Address Translation Unit

[Suzuki K Poulose]

Hi Mathieu,

On 20/06/1822:41, Mathieu Poirier wrote:
> Hi Suzuki,
>
> On Mon, Jun 18, 2018 at 11:56:16AM +0100, Suzuki K Poulose wrote:
> > Add the initial support for Coresight Address Translation Unit, which
> > augments the TMC in Coresight SoC-600 by providing an improved Scatter
> > Gather mechanism. CATU is always connected to a single TMC-ETR and
> > converts the AXI address with a translated address (from a given SG
> > table with specific format). The CATU should be programmed in pass
> > through mode and enabled if the ETR doesn't translation by CATU.
>
> To me this sentence look broken.

Yes, it is broken. It should have been :

"The CATU should be programmed in pass through mode and enabled
even if the ETR doesn't use the translation by CATU."


> > +static int catu_disable_hw(struct catu_drvdata *drvdata)
> > +{
> > +	int rc = 0;
> > +
> > +	if (catu_wait_for_ready(drvdata)) {
> > +		dev_info(drvdata->dev, "Timeout while waiting for READY\n");
> > +		rc = -EAGAIN;
> > +	}
> > +
> > +	catu_write_control(drvdata, 0);
>
> Is waiting for the ready bit before switching the component off comes from
> experimentation with the HW (i.e FPGA)?  From what the reference manual
> indicate, CONTROL.ENABLE should be set to 0 first, and then wait for
> STATUS.READY.

You're right. It should be in the reverse order. I will fix it in the next version.

Thanks
Suzuki