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

From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: mike.leach@linaro.org, linux-arm-kernel@lists.infradead.org,
	devicetree@vger.kernel.org, coresight@lists.linaro.org,
	linux-doc@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	robh+dt@kernel.org, maxime@cerno.tech, liviu.dudau@arm.com,
	sudeep.holla@arm.com, lorenzo.pieralisi@arm.com,
	agross@kernel.org, corbet@lwn.net
Subject: Re: [PATCH v9 08/15] coresight: cti: Enable CTI associated with devices.
Date: Fri, 21 Feb 2020 09:51:34 -0700	[thread overview]
Message-ID: <20200221165134.GA25043@xps15> (raw)
In-Reply-To: <04b739fd-7bb3-bd28-8013-918e7d4dfcb7@arm.com>

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>