[PATCH] coresight-etm4: Fix for() loop drvdata->nr_addr_cmp range bug

[Mike Leach]

Hi

On Tue, 28 Feb 2023 at 11:27, James Clark <james.clark at arm.com> wrote:
>
>
>
> On 27/02/2023 23:54, Steve Clevenger wrote:
> > In etm4_enable_hw, fix for() loop range to represent address comparator pairs.
> >
> > Signed-off-by: Steve Clevenger <scclevenger at os.amperecomputing.com>
> > ---
> >  drivers/hwtracing/coresight/coresight-etm4x-core.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > index 1ea8f173cca0..104333c2c8a3 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > @@ -472,7 +472,7 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
> >               if (etm4x_sspcicrn_present(drvdata, i))
> >                       etm4x_relaxed_write32(csa, config->ss_pe_cmp[i], TRCSSPCICRn(i));
> >       }
> > -     for (i = 0; i < drvdata->nr_addr_cmp; i++) {
> > +     for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) {
> >               etm4x_relaxed_write64(csa, config->addr_val[i], TRCACVRn(i));
> >               etm4x_relaxed_write64(csa, config->addr_acc[i], TRCACATRn(i));
> >       }
>
> Reviewed-by: James Clark <james.clark at arm.com>
>
> Are there other ones in coresight-etm3x-sysfs.c:reset_store() and
> coresight-etm3x-core.c:etm_enable_hw()? Or is etm3 different?

For reasons passing understanding - the etm3x code does the 2 *
multiplier at the point that config->nr_addr_cmp is initialised, so it
reflects the number of comparators rather than the number of pairs.
That said the comments and docs in
./Documents/ABI/testing/sysfs-bus-coresight-devices-etm3x claim that
the value is still the number of pairs.

Mike



--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK