From: Sven Van Asbroeck <thesven73@gmail.com>
To: "Enrico Weigelt, metux IT consult" <lkml@metux.net>
Cc: "Rob Herring" <robh+dt@kernel.org>,
"Linus Walleij" <linus.walleij@linaro.org>,
"Lee Jones" <lee.jones@linaro.org>,
mark.rutland@arm.com, "Andreas Färber" <afaerber@suse.de>,
treding@nvidia.com, "David Lechner" <david@lechnology.com>,
noralf@tronnes.org, johan@kernel.org,
"Michal Simek" <monstr@monstr.eu>,
michal.vokac@ysoft.com, "Arnd Bergmann" <arnd@arndb.de>,
"Greg KH" <gregkh@linuxfoundation.org>,
john.garry@huawei.com, geert+renesas@glider.be,
robin.murphy@arm.com,
"Paul Gortmaker" <paul.gortmaker@windriver.com>,
sebastien.bourdelin@savoirfairelinux.com, icenowy@aosc.io,
"Stuart Yoder" <stuyoder@gmail.com>,
"J. Kiszka" <jan.kiszka@siemens.com>,
maxime.ripard@bootlin.com,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
netdev <netdev@vger.kernel.org>
Subject: Re: [PATCH v10 0/7] Add Fieldbus subsystem + support HMS Profinet card
Date: Wed, 17 Apr 2019 10:37:11 -0400 [thread overview]
Message-ID: <CAGngYiVSibcSas+cGPVkvBb-kgUnDAbgd3m59yyqwp5j1D+Cew@mail.gmail.com> (raw)
In-Reply-To: <23a25601-ed98-5348-9bac-bf8fc2baea5e@metux.net>
On Tue, Apr 16, 2019 at 5:21 PM Enrico Weigelt, metux IT consult
<lkml@metux.net> wrote:
>
> Yet another question: does each fieldbus_dev instance talk to exactly
> one plc process memory, or can there be many ?
I'm by no means a fieldbus expert, so I had a little chat with one of
the fieldbus
people in the company here.
AFAIK if multiple plcs connect to the same device, all of them 'see' the same
process memory for that device. Any mechanism to prevent these plcs from
racing with each other is implemented in the application software. Could
be handshaking, could be each plc dealing with a separate section of
the process memory.
So for a fieldbus *device* (which is what this subsystem deals with) there can
only be a single process memory. So we have a single devnode per device.
A fieldbus *controller* would have one process memory per device it connects to.
But this subsystem does not deal with controllers.
This is my understanding, but I'd appreciate your input if I have overlooked
something.
next prev parent reply other threads:[~2019-04-17 14:37 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-09 14:42 [PATCH v10 0/7] Add Fieldbus subsystem + support HMS Profinet card Sven Van Asbroeck
2019-04-09 14:42 ` [PATCH v10 1/7] fieldbus_dev: add Fieldbus Device subsystem Sven Van Asbroeck
2019-04-16 11:13 ` Greg KH
2019-04-09 14:42 ` [PATCH v10 2/7] anybus-s: support HMS Anybus-S bus Sven Van Asbroeck
2019-04-09 14:42 ` [PATCH v10 3/7] anybus-s: support the Arcx anybus controller Sven Van Asbroeck
2019-04-09 14:42 ` [PATCH v10 4/7] dt-bindings: anybus-controller: document devicetree binding Sven Van Asbroeck
2019-04-09 15:50 ` Rob Herring
2019-04-09 17:16 ` Sven Van Asbroeck
2019-04-09 17:31 ` Sven Van Asbroeck
2019-04-09 21:09 ` Rob Herring
2019-04-10 13:11 ` Sven Van Asbroeck
2019-04-16 11:11 ` Greg KH
2019-04-09 14:42 ` [PATCH v10 5/7] dt-bindings: Add vendor prefix for arcx / Archronix Sven Van Asbroeck
2019-04-09 14:42 ` [PATCH v10 6/7] fieldbus_dev: support HMS Profinet IRT industrial controller Sven Van Asbroeck
2019-04-09 14:42 ` [PATCH v10 7/7] staging: fieldbus_dev: add TODO Sven Van Asbroeck
2019-04-15 17:41 ` [PATCH v10 0/7] Add Fieldbus subsystem + support HMS Profinet card Enrico Weigelt, metux IT consult
2019-04-15 18:31 ` Sven Van Asbroeck
2019-04-16 16:49 ` Enrico Weigelt, metux IT consult
2019-04-16 18:56 ` Sven Van Asbroeck
2019-04-16 21:18 ` Enrico Weigelt, metux IT consult
2019-04-16 21:49 ` Sven Van Asbroeck
2019-04-16 22:12 ` Sven Van Asbroeck
2019-04-18 8:32 ` Enrico Weigelt, metux IT consult
2019-04-18 17:34 ` Sven Van Asbroeck
2019-04-24 9:40 ` Enrico Weigelt, metux IT consult
2019-04-24 10:26 ` Oliver Hartkopp
2019-04-24 11:00 ` Andreas Färber
2019-04-24 11:48 ` Oliver Hartkopp
2019-04-24 15:10 ` Sven Van Asbroeck
2019-04-29 13:54 ` Enrico Weigelt, metux IT consult
2019-04-17 14:37 ` Sven Van Asbroeck [this message]
2019-04-17 17:04 ` Andreas Färber
2019-04-17 20:13 ` Enrico Weigelt, metux IT consult
2019-04-25 8:26 ` Lee Jones
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