devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Suzuki Kuruppassery Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>,
	Coresight ML <coresight@lists.linaro.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	devicetree@vger.kernel.org,
	"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>
Subject: Re: [PATCH v5 07/14] coresight: cti: Add device tree support for custom CTI.
Date: Fri, 29 Nov 2019 14:11:13 -0700	[thread overview]
Message-ID: <CANLsYkxqO71aBzf=BqcFDWccp3XH3gXc4OESgRy0-rTEe27fJA@mail.gmail.com> (raw)
In-Reply-To: <35357ff3-2b1e-764e-cfbd-65bcc7a4faa6@arm.com>

On Fri, 29 Nov 2019 at 07:16, Suzuki Kuruppassery Poulose
<suzuki.poulose@arm.com> wrote:
>
> On 25/11/2019 21:22, Mathieu Poirier wrote:
> > On Tue, Nov 19, 2019 at 11:19:05PM +0000, Mike Leach wrote:
> >> Adds support for CTIs whose connections are implementation defined at
> >> hardware design time, and not constrained by v8 architecture.
> >>
> >> These CTIs have no standard connection setup, all the settings have to
> >> be defined in the device tree files. The patch creates a set of connections
> >> and trigger signals based on the information provided.
> >>
> >> Signed-off-by: Mike Leach <mike.leach@linaro.org>
> >> ---
> >>   .../coresight/coresight-cti-platform.c        | 250 +++++++++++++++++-
> >>   .../hwtracing/coresight/coresight-cti-sysfs.c |  11 +
> >>   2 files changed, 257 insertions(+), 4 deletions(-)
>
> >> +static int cti_plat_create_impdef_connections(struct device *dev,
> >> +                                          struct cti_drvdata *drvdata)
> >> +{
> >> +    int rc = 0;
> >> +    struct fwnode_handle *fwnode = dev_fwnode(dev);
> >> +    struct fwnode_handle *child = NULL;
> >> +
> >> +    if (IS_ERR_OR_NULL(fwnode))
> >> +            return -EINVAL;
> >> +
> >> +    fwnode_for_each_child_node(fwnode, child) {
> >> +            if (cti_plat_node_name_eq(child, CTI_DT_CONNS))
> >> +                    rc = cti_plat_create_connection(dev, drvdata, child);
> >> +            if (rc != 0)
> >> +                    break;
> >> +    }
> >> +    fwnode_handle_put(child);
> >
> > As far as I can tell we don't need to call fwnode_handle_put()?
>
> Actually we do, if we break the scan in between, at least for of_nodes.
> I had to literally look it down all the way down to confirm this.
>
> So for CONFIG_OF it ends up in of_get_next_available_child(), which
> drops the ref on "prev" and grabs the "next". So in case we break
> the loop, we must drop the ref on the child.

Well spotted.

> Otherwise, the last
> result would be NULL, which would have dropped the ref on the "last"
> valid entry. And this is harmless with a NULL ptr.
>
> Suzuki

  reply	other threads:[~2019-11-29 21:11 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-19 23:18 [PATCH v5 00/14] CoreSight CTI Driver Mike Leach
2019-11-19 23:18 ` [PATCH v5 01/14] coresight: cti: Initial " Mike Leach
2019-11-21 20:21   ` Mathieu Poirier
2019-11-29 12:05     ` Mike Leach
2019-12-03 16:53       ` Mathieu Poirier
2019-11-25 19:03   ` Suzuki Kuruppassery Poulose
2019-11-29 12:06     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 02/14] coresight: cti: Add sysfs coresight mgmt reg access Mike Leach
2019-11-22 17:19   ` Mathieu Poirier
2019-11-19 23:19 ` [PATCH v5 03/14] coresight: cti: Add sysfs access to program function regs Mike Leach
2019-11-27 18:26   ` Suzuki Kuruppassery Poulose
2019-11-29 12:47     ` Mike Leach
2019-11-28 10:54   ` Suzuki Kuruppassery Poulose
2019-11-28 17:20     ` Mathieu Poirier
2019-11-28 18:00       ` Suzuki Kuruppassery Poulose
2019-11-29 12:50     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 04/14] coresight: cti: Add sysfs trigger / channel programming API Mike Leach
2019-11-22 18:40   ` Mathieu Poirier
2019-11-27 18:40   ` Suzuki Kuruppassery Poulose
2019-11-29 13:01     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 05/14] dt-bindings: arm: Adds CoreSight CTI hardware definitions Mike Leach
2019-11-20 19:06   ` Mathieu Poirier
2019-11-20 22:39     ` Mike Leach
2019-11-22 23:33   ` Rob Herring
2019-11-29 13:50     ` Mike Leach
2019-11-29 14:12       ` Suzuki Kuruppassery Poulose
2019-11-28 18:38   ` Suzuki Kuruppassery Poulose
2019-11-29 13:57     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 06/14] coresight: cti: Add device tree support for v8 arch CTI Mike Leach
2019-11-25 19:00   ` Mathieu Poirier
2019-11-29 11:33   ` Suzuki Kuruppassery Poulose
2019-12-03 10:59     ` Mike Leach
2019-12-03 11:28       ` Suzuki Kuruppassery Poulose
2019-12-03 12:25         ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 07/14] coresight: cti: Add device tree support for custom CTI Mike Leach
2019-11-25 21:22   ` Mathieu Poirier
2019-11-29 14:16     ` Suzuki Kuruppassery Poulose
2019-11-29 21:11       ` Mathieu Poirier [this message]
2019-11-29 14:18   ` Suzuki Kuruppassery Poulose
2019-12-03 14:05     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 08/14] coresight: cti: Enable CTI associated with devices Mike Leach
2019-11-25 22:45   ` Mathieu Poirier
2019-12-05 16:33     ` Mike Leach
2019-11-29 18:28   ` Suzuki Kuruppassery Poulose
2019-11-29 21:25     ` Mathieu Poirier
2019-12-05 16:33     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 09/14] coresight: cti: Add connection information to sysfs Mike Leach
2019-11-27 18:09   ` Mathieu Poirier
2019-12-06 16:24     ` Mike Leach
2019-12-02  9:47   ` Suzuki Kuruppassery Poulose
2019-12-06 16:24     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 10/14] dt-bindings: qcom: Add CTI options for qcom msm8916 Mike Leach
2019-11-27 18:18   ` Mathieu Poirier
2019-11-19 23:19 ` [PATCH v5 11/14] dt-bindings: arm: Juno platform - add CTI entries to device tree Mike Leach
2019-11-27 18:25   ` Mathieu Poirier
2019-11-19 23:19 ` [PATCH v5 12/14] dt-bindings: hisilicon: Add CTI bindings for hi-6220 Mike Leach
2019-11-19 23:19 ` [PATCH v5 13/14] docs: coresight: Update documentation for CoreSight to cover CTI Mike Leach
2019-11-27 19:00   ` Mathieu Poirier
2019-12-02 10:43   ` Suzuki Kuruppassery Poulose
2019-12-06 17:39     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 14/14] docs: sysfs: coresight: Add sysfs ABI documentation for CTI Mike Leach
2019-11-27 19:08   ` Mathieu Poirier

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CANLsYkxqO71aBzf=BqcFDWccp3XH3gXc4OESgRy0-rTEe27fJA@mail.gmail.com' \
    --to=mathieu.poirier@linaro.org \
    --cc=coresight@lists.linaro.org \
    --cc=devicetree@vger.kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=mike.leach@linaro.org \
    --cc=suzuki.poulose@arm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).