Messages in this thread | | | Date | Wed, 7 Nov 2018 11:23:50 +0800 | From | leo.yan@linaro ... | Subject | Re: [PATCH 3/3] coresight: etm3x: Release CLAIM tag when operated from perf |
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Hi Mathieu,
On Mon, Nov 05, 2018 at 03:26:30PM -0700, Mathieu Poirier wrote: > This patch deals with the release of the CLAIM tag when the ETM is > operated from perf. Otherwise the tag is left asserted and subsequent > requests to use the device fail. > > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> > --- > drivers/hwtracing/coresight/coresight-etm3x.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c > index fd5c4cca7db5..000796394662 100644 > --- a/drivers/hwtracing/coresight/coresight-etm3x.c > +++ b/drivers/hwtracing/coresight/coresight-etm3x.c > @@ -603,6 +603,8 @@ static void etm_disable_perf(struct coresight_device *csdev) > */ > etm_set_pwrdwn(drvdata); > > + coresight_disclaim_device_unlocked(drvdata->base); > +
Just remind, this isn't consistent with the sequency in function etm_disable_hw(), which has the reversed sequence between etm_set_pwrdwn() and coresight_disclaim_device_unlocked().
Not sure which one sequence is more suitable, at the first glance, accessing register after pwrdwn related operation might have risk for deadlock?
Thanks, Leo Yan
> CS_LOCK(drvdata->base); > } > > -- > 2.7.4 >
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