Re: [PATCH v9 08/15] coresight: cti: Enable CTI associated with devices.

Mathieu Poirier
2020-02-21T16:51:38Z

On Fri, Feb 21, 2020 at 12:20:17AM +0000, Suzuki K Poulose wrote:
> Hi Mike
>
> Sorry for the delay. one minor comment below.
>
> On 02/10/2020 09:39 PM, Mike Leach wrote:
> > The CoreSight subsystem enables a path of devices from source to sink.
> > Any CTI devices associated with the path devices must be enabled at the
> > same time.
> >
> > This patch adds an associated coresight_device element to the main
> > coresight device structure, and uses this to create associations between
> > the CTI and other devices based on the device tree data. The associated
> > device element is used to enable CTI in conjunction with the path elements.
> >
> > CTI devices are reference counted so where a single CTI is associated with
> > multiple elements on the path, it will be enabled on the first associated
> > device enable, and disabled with the last associated device disable.
> >
> > Signed-off-by: Mike Leach <mike.leach@linaro.org>
> > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> > ---
> > drivers/hwtracing/coresight/coresight-cti.c | 129 +++++++++++++++++++
> > drivers/hwtracing/coresight/coresight-cti.h | 1 +
> > drivers/hwtracing/coresight/coresight-priv.h | 12 ++
> > drivers/hwtracing/coresight/coresight.c | 71 +++++++++-
> > include/linux/coresight.h | 4 +
> > 5 files changed, 212 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-cti.c b/drivers/hwtracing/coresight/coresight-cti.c
> > index 77c2af247917..c4494923d030 100644
> > --- a/drivers/hwtracing/coresight/coresight-cti.c
> > +++ b/drivers/hwtracing/coresight/coresight-cti.c
> > @@ -4,6 +4,7 @@
> > * Author: Mike Leach <mike.leach@linaro.org>
> > */
> > +#include <linux/property.h>
> > #include "coresight-cti.h"
> > /**
> > @@ -440,6 +441,131 @@ int cti_channel_setop(struct device *dev, enum cti_chan_set_op op,
> > return err;
> > }
> > +/*
> > + * Look for a matching connection device name in the list of connections.
> > + * If found then swap in the csdev name, set trig con association pointer
> > + * and return found.
> > + */
> > +static bool
> > +cti_match_fixup_csdev(struct cti_device *ctidev, const char *node_name,
> > + struct coresight_device *csdev)
> > +{
> > + struct cti_trig_con *tc;
> > + const char *csdev_name;
> > +
> > + list_for_each_entry(tc, &ctidev->trig_cons, node) {
> > + if (tc->con_dev_name) {
> > + if (!strcmp(node_name, tc->con_dev_name)) {
> > + /* match: so swap in csdev name & dev */
> > + csdev_name = dev_name(&csdev->dev);
> > + tc->con_dev_name =
> > + devm_kstrdup(&csdev->dev, csdev_name,
> > + GFP_KERNEL);
>
> In the extreme rare case of an allocation failure, we may want to
> check if the allocation was successful or not, rather than silently
> ignoring it. With that fixed,

Line 419 and 423 in patch 1 need the same attention.

>
> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>