From: Georgi Djakov <georgi.djakov@linaro.org>
To: Joe Perches <joe@perches.com>
Cc: linux-pm@vger.kernel.org, gregkh@linuxfoundation.org,
rjw@rjwysocki.net, robh+dt@kernel.org, mturquette@baylibre.com,
khilman@baylibre.com, vincent.guittot@linaro.org,
skannan@codeaurora.org, bjorn.andersson@linaro.org,
amit.kucheria@linaro.org, seansw@qti.qualcomm.com,
daidavid1@codeaurora.org, evgreen@chromium.org,
mark.rutland@arm.com, lorenzo.pieralisi@arm.com,
abailon@baylibre.com, maxime.ripard@bootlin.com, arnd@arndb.de,
thierry.reding@gmail.com, ksitaraman@nvidia.com,
sanjayc@nvidia.com, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-arm-msm@vger.kernel.org, linux-tegra@vger.kernel.org
Subject: Re: [PATCH v10 1/7] interconnect: Add generic on-chip interconnect API
Date: Wed, 28 Nov 2018 20:18:04 +0200 [thread overview]
Message-ID: <82026d31-39e8-08f1-761b-c0b3ccf8ce20@linaro.org> (raw)
In-Reply-To: <5d16a4a57ed5529299d7b73e13a249add00b1afe.camel@perches.com>
Hi Joe,
On 11/27/18 20:35, Joe Perches wrote:
> On Tue, 2018-11-27 at 20:03 +0200, Georgi Djakov wrote:
>> This patch introduces a new API to get requirements and configure the
>> interconnect buses across the entire chipset to fit with the current
>> demand.
>
> trivial notes:
>
>> diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
> []
>> +static int apply_constraints(struct icc_path *path)
>> +{
>> + struct icc_node *next, *prev = NULL;
>> + int ret = -EINVAL;
>> + int i;
>> +
>> + for (i = 0; i < path->num_nodes; i++, prev = next) {
>> + struct icc_provider *p;
>> +
>> + next = path->reqs[i].node;
>> + /*
>> + * Both endpoints should be valid master-slave pairs of the
>> + * same interconnect provider that will be configured.
>> + */
>> + if (!prev || next->provider != prev->provider)
>> + continue;
>> +
>> + p = next->provider;
>> +
>> + /* set the constraints */
>> + ret = p->set(prev, next);
>> + if (ret)
>> + goto out;
>> + }
>> +out:
>> + return ret;
>> +}
>
> The use of ", prev = next" appears somewhat tricky code.
> Perhaps move the assignment of prev to the bottom of the loop.
> Perhaps the temporary p assignment isn't useful either.
>
>> +int icc_set(struct icc_path *path, u32 avg_bw, u32 peak_bw)
>> +{
> []
>> + ret = apply_constraints(path);
>> + if (ret)
>> + pr_debug("interconnect: error applying constraints (%d)", ret);
>
> Ideally all pr_<foo> formats should end in '\n'
>
>> +static struct icc_node *icc_node_create_nolock(int id)
>> +{
>> + struct icc_node *node;
>> +
>> + /* check if node already exists */
>> + node = node_find(id);
>> + if (node)
>> + goto out;
>> +
>> + node = kzalloc(sizeof(*node), GFP_KERNEL);
>> + if (!node) {
>> + node = ERR_PTR(-ENOMEM);
>> + goto out;
>
> Generally, this code appears to overly rely on goto when
> direct returns could be more readable.
>
>> + }
>> +
>> + id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL);
>> + if (WARN(id < 0, "couldn't get idr")) {
>
> This seems to unnecessarily hide the id < 0 test in a WARN
>
> Why is this a WARN and not a simpler
> if (id < 0) {
> [ pr_err(...); or WARN(1, ...); ]
>
>> + kfree(node);
>> + node = ERR_PTR(id);
>> + goto out;
>> + }
>> +
>> + node->id = id;
>> +
>> +out:
>> + return node;
>> +}
Thank you for helping to improve the code. The above suggestions make it
cleaner indeed.
> []
>> diff --git a/include/linux/interconnect.h b/include/linux/interconnect.h
> []
>> +/* macros for converting to icc units */
>> +#define bps_to_icc(x) (1)
>> +#define kBps_to_icc(x) (x)
> []
>> +#define MBps_to_icc(x) (x * 1000)
>> +#define GBps_to_icc(x) (x * 1000 * 1000)
>> +#define kbps_to_icc(x) (x / 8 + ((x) % 8 ? 1 : 0))
>> +#define Mbps_to_icc(x) (x * 1000 / 8 )
>> +#define Gbps_to_icc(x) (x * 1000 * 1000 / 8)
>
> The last 5 macros should parenthesize x
Oops.. obviously i forgot to run checkpatch --strict. Will fix!
BR,
Georgi
next prev parent reply other threads:[~2018-11-28 18:18 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-27 18:03 [PATCH v10 0/8] Introduce on-chip interconnect API Georgi Djakov
2018-11-27 18:03 ` [PATCH v10 1/7] interconnect: Add generic " Georgi Djakov
2018-11-27 18:35 ` Joe Perches
2018-11-28 18:18 ` Georgi Djakov [this message]
2018-12-01 0:38 ` Evan Green
2018-12-05 15:57 ` Georgi Djakov
2018-12-05 16:16 ` Rob Herring
2018-12-07 15:24 ` Georgi Djakov
2018-11-27 18:03 ` [PATCH v10 2/7] dt-bindings: Introduce interconnect binding Georgi Djakov
2018-12-01 0:38 ` Evan Green
2018-11-27 18:03 ` [PATCH v10 3/7] interconnect: Allow endpoints translation via DT Georgi Djakov
2018-12-01 0:38 ` Evan Green
2018-12-05 15:59 ` Georgi Djakov
2018-11-27 18:03 ` [PATCH v10 4/7] interconnect: Add debugfs support Georgi Djakov
2018-11-27 18:03 ` [PATCH v10 5/7] interconnect: qcom: Add sdm845 interconnect provider driver Georgi Djakov
2018-12-01 0:39 ` Evan Green
2018-12-05 16:00 ` Georgi Djakov
2018-12-06 21:53 ` David Dai
2018-11-27 18:03 ` [PATCH v10 6/7] arm64: dts: sdm845: Add interconnect provider DT nodes Georgi Djakov
2018-12-01 0:39 ` Evan Green
2018-12-05 16:01 ` Georgi Djakov
2018-11-27 18:03 ` [PATCH v10 7/7] MAINTAINERS: add a maintainer for the interconnect API Georgi Djakov
2018-12-05 20:41 ` [PATCH v10 0/8] Introduce on-chip " Evan Green
2018-12-06 14:55 ` Greg KH
2018-12-07 10:06 ` Georgi Djakov
2018-12-10 9:04 ` Rafael J. Wysocki
2018-12-10 10:18 ` Georgi Djakov
2018-12-10 11:00 ` Rafael J. Wysocki
2018-12-10 14:50 ` Georgi Djakov
2018-12-11 6:58 ` Greg Kroah-Hartman
2018-12-17 11:17 ` Georgi Djakov
2019-01-10 14:19 ` Georgi Djakov
2019-01-10 16:29 ` Greg Kroah-Hartman
2019-01-10 16:34 ` Georgi Djakov
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=82026d31-39e8-08f1-761b-c0b3ccf8ce20@linaro.org \
--to=georgi.djakov@linaro.org \
--cc=abailon@baylibre.com \
--cc=amit.kucheria@linaro.org \
--cc=arnd@arndb.de \
--cc=bjorn.andersson@linaro.org \
--cc=daidavid1@codeaurora.org \
--cc=devicetree@vger.kernel.org \
--cc=evgreen@chromium.org \
--cc=gregkh@linuxfoundation.org \
--cc=joe@perches.com \
--cc=khilman@baylibre.com \
--cc=ksitaraman@nvidia.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=lorenzo.pieralisi@arm.com \
--cc=mark.rutland@arm.com \
--cc=maxime.ripard@bootlin.com \
--cc=mturquette@baylibre.com \
--cc=rjw@rjwysocki.net \
--cc=robh+dt@kernel.org \
--cc=sanjayc@nvidia.com \
--cc=seansw@qti.qualcomm.com \
--cc=skannan@codeaurora.org \
--cc=thierry.reding@gmail.com \
--cc=vincent.guittot@linaro.org \
/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).