From: Mark Brown <broonie@kernel.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Adrian Fiergolski <adrian.fiergolski@fastree3d.com>,
Lukas Wunner <lukas@wunner.de>, kernel test robot <lkp@intel.com>,
Rob Herring <robh+dt@kernel.org>,
linux-spi <linux-spi@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/2] spi: Add the SPI daisy chain support.
Date: Tue, 7 Jul 2020 11:25:11 +0100 [thread overview]
Message-ID: <20200707102511.GE4870@sirena.org.uk> (raw)
In-Reply-To: <CAMuHMdXK92qO8KB6ejc6LLmfFsy=dZY18vNJGh+CKRZBAov-JA@mail.gmail.com>
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On Mon, Jul 06, 2020 at 09:57:53PM +0200, Geert Uytterhoeven wrote:
> On Mon, Jul 6, 2020 at 6:18 PM Mark Brown <broonie@kernel.org> wrote:
> > It would really help to have an example of how a client device will use
> > this, right now it's a bit hard to follow. Overall it feels like this
> > should be better abstracted, right now there's lots of ifdefs throughout
> > the code which make things unclear and also seem like they're going to
> > be fragile long term since realistically very few systems will be using
> > this.
> Can't the ifdefs be avoided by implementing this as a new SPI controller?
> I.e. the daisy chain driver will operate as a slave of the parent SPI
> controller,
> but will expose a new SPI bus to the daisy-chained slaves.
Yes, that might work. I do worry about locking issues with having a SPI
controller connected via SPI but we mostly only lock at the controller
level so it's probably fine. Not sure how this would perform either.
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next prev parent reply other threads:[~2020-07-07 10:25 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-03 14:12 [PATCH 1/2] spi: Add the SPI daisy chain support Adrian Fiergolski
2020-07-03 14:12 ` [PATCH 2/2] dt-bindings: Add documentation for SPI daisy chain driver Adrian Fiergolski
2020-07-03 22:32 ` [PATCH 1/2] spi: Add the SPI daisy chain support kernel test robot
2020-07-04 0:18 ` kernel test robot
2020-07-06 9:22 ` [PATCH v2 " Adrian Fiergolski
2020-07-06 9:22 ` [PATCH v2 2/2] dt-bindings: Add documentation for SPI daisy chain driver Adrian Fiergolski
2020-07-06 15:10 ` Geert Uytterhoeven
2020-07-06 15:19 ` Adrian Fiergolski
2020-07-06 15:32 ` Geert Uytterhoeven
2020-07-06 16:22 ` Mark Brown
2020-07-07 9:55 ` Adrian Fiergolski
2020-07-06 16:18 ` [PATCH v2 1/2] spi: Add the SPI daisy chain support Mark Brown
2020-07-06 19:57 ` Geert Uytterhoeven
2020-07-07 10:25 ` Mark Brown [this message]
2020-07-07 11:06 ` Adrian Fiergolski
2020-07-07 10:53 ` Adrian Fiergolski
2020-07-07 11:21 ` Mark Brown
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