From: Maxime Ripard <maxime@cerno.tech>
To: Chen-Yu Tsai <wens@csie.org>
Cc: Alexander Kochetkov <al.kochet@gmail.com>,
Mark Brown <broonie@kernel.org>,
linux-spi@vger.kernel.org,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] spi: spi-sun6i: implement DMA-based transfer mode
Date: Wed, 21 Oct 2020 17:03:48 +0200 [thread overview]
Message-ID: <20201021150348.g2anzbqalhrmypdl@gilmour.lan> (raw)
In-Reply-To: <CAGb2v64ruUf7Lv-cHZTRPs-U-gOboGtTwOB3+qtxZTFyLVFLjg@mail.gmail.com>
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On Tue, Oct 20, 2020 at 11:52:34AM +0800, Chen-Yu Tsai wrote:
> On Tue, Oct 20, 2020 at 1:43 AM Alexander Kochetkov <al.kochet@gmail.com> wrote:
> >
> >
> >
> > > 19 окт. 2020 г., в 11:21, Maxime Ripard <maxime@cerno.tech> написал(а):
> > >
> > > Hi!
> > >
> > > On Thu, Oct 15, 2020 at 06:47:40PM +0300, Alexander Kochetkov wrote:
> > >> DMA-based transfer will be enabled if data length is larger than FIFO size
> > >> (64 bytes for A64). This greatly reduce number of interrupts for
> > >> transferring data.
> > >>
> > >> For smaller data size PIO mode will be used. In PIO mode whole buffer will
> > >> be loaded into FIFO.
> > >>
> > >> If driver failed to request DMA channels then it fallback for PIO mode.
> > >>
> > >> Tested on SOPINE (https://www.pine64.org/sopine/)
> > >>
> > >> Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
> > >
> > > Thanks for working on this, it's been a bit overdue
> >
> > Hi, Maxime!
> >
> > We did custom A64 based computation module for our product.
> > Do you mean that A64 is obsolete or EOL product?
> > If so, can you recommend active replacement for A64 from Allwinner same price?
>
> I believe what Maxime meant was that DMA transfer for SPI is a long
> sought-after feature, but no one had finished it.
Yeah, that's what I meant :)
Maxime
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prev parent reply other threads:[~2020-10-21 15:03 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-15 15:47 [PATCH] spi: spi-sun6i: implement DMA-based transfer mode Alexander Kochetkov
2020-10-19 8:21 ` Maxime Ripard
2020-10-19 13:17 ` Alexander Kochetkov
2020-10-21 16:39 ` Maxime Ripard
2020-10-19 17:43 ` Alexander Kochetkov
2020-10-20 3:52 ` Chen-Yu Tsai
2020-10-21 15:03 ` Maxime Ripard [this message]
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