From: Wolfram Sang <wsa@the-dreams.de>
To: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Cc: Ray Jui <ray.jui@broadcom.com>, Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
linux-i2c@vger.kernel.org, devicetree@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
bcm-kernel-feedback-list@broadcom.com,
Shreesha Rajashekar <shreesha.rajashekar@broadcom.com>,
Michael Cheng <ccheng@broadcom.com>
Subject: Re: [PATCH v5 2/8] i2c: iproc: Add slave mode support
Date: Tue, 2 Apr 2019 11:01:05 +0200 [thread overview]
Message-ID: <20190402090105.GA2960@kunai> (raw)
In-Reply-To: <CAHO=5PG=wsYZqa0+BVbvSKgWg9NgDOrDc8J2DoXn4BRRWmDvRg@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 1001 bytes --]
> > >> + /* RANDOM SLAVE STRETCH time - 20ms*/
> > >
> > > What is a "random stretch time"? 20ms sounds like a lot. Also, missing
> > > space before comment terminator.
> > >
> >
> > Rayagonda,
> >
> > Could you please help to comment on the choice of the 20 ms to allow
> > clock stretch from the slave? In probably all cases, the slave should
> > not need more than 1 ms? 20 ms does seem way too long as Wolfram pointed
> > out.
>
> In fact we are programming max slave stretch time ie 25ms, comment
> should be correcting.
> Its maximum time for slave to complete read/write operation, if slave
> is done with read/write then clock will not be stretched further, it
> will be released immediately.
Ah, now I see. This is a protection against the slave stretching the
clock forever. This makes sense.
> Hence I feel no harm in programming max timeout value.
I agree. "Random stretch" is just a bit confusing as a name. "Maximum"
would have been more clear IMO.
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next prev parent reply other threads:[~2019-04-02 9:01 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-14 17:57 [PATCH v5 0/8] iProc I2C slave mode and NIC mode Ray Jui
2019-02-14 17:57 ` [PATCH v5 1/8] i2c: iproc: Extend I2C read up to 255 bytes Ray Jui
2019-03-27 22:17 ` Wolfram Sang
2019-04-01 21:35 ` Ray Jui
2019-02-14 17:57 ` [PATCH v5 2/8] i2c: iproc: Add slave mode support Ray Jui
2019-03-27 22:14 ` Wolfram Sang
2019-03-27 22:41 ` Wolfram Sang
2019-04-01 21:33 ` Ray Jui
2019-04-02 8:24 ` Rayagonda Kokatanur
2019-04-02 9:01 ` Wolfram Sang [this message]
2019-02-14 17:57 ` [PATCH v5 3/8] dt-bindings: i2c: iproc: make 'interrupts' optional Ray Jui
2019-02-14 22:25 ` Rob Herring
2019-02-14 17:57 ` [PATCH v5 4/8] i2c: iproc: add polling support Ray Jui
2019-02-14 17:57 ` [PATCH v5 5/8] i2c: iproc: use wrapper for read/write access Ray Jui
2019-02-14 17:57 ` [PATCH v5 6/8] dt-bindings: i2c: iproc: add "brcm,iproc-nic-i2c" compatible string Ray Jui
2019-02-14 22:26 ` Rob Herring
2019-03-27 22:24 ` Wolfram Sang
2019-04-01 21:43 ` Ray Jui
2019-04-02 10:17 ` Wolfram Sang
2019-02-14 17:57 ` [PATCH v5 7/8] i2c: iproc: add NIC I2C support Ray Jui
2019-04-02 10:27 ` Wolfram Sang
2019-04-02 17:57 ` Ray Jui
2019-04-03 1:10 ` Ray Jui
2019-02-14 17:57 ` [PATCH v5 8/8] arm64: dts: Stingray: Add NIC i2c device node Ray Jui
2019-02-22 20:04 ` [PATCH v5 0/8] iProc I2C slave mode and NIC mode Ray Jui
2019-03-22 16:40 ` Florian Fainelli
2019-03-27 22:27 ` Wolfram Sang
2019-04-01 21:44 ` Ray Jui
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=20190402090105.GA2960@kunai \
--to=wsa@the-dreams.de \
--cc=bcm-kernel-feedback-list@broadcom.com \
--cc=ccheng@broadcom.com \
--cc=devicetree@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-i2c@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=ray.jui@broadcom.com \
--cc=rayagonda.kokatanur@broadcom.com \
--cc=robh+dt@kernel.org \
--cc=shreesha.rajashekar@broadcom.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).