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Message-ID: <CAL9mu0LAnT+AfjpGs0O-MD2HYrpnQRmrj6qXtJQrJi9kbQLPUw@mail.gmail.com>
Date: Fri, 22 May 2020 22:57:10 +0800
From: dillon min <dillon.minfei@...il.com>
To: Mark Brown <broonie@...nel.org>
Cc: Rob Herring <robh+dt@...nel.org>, p.zabel@...gutronix.de,
Maxime Coquelin <mcoquelin.stm32@...il.com>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@...r.kernel.org>,
Alexandre Torgue <alexandre.torgue@...com>,
thierry.reding@...il.com, Sam Ravnborg <sam@...nborg.org>,
Dave Airlie <airlied@...ux.ie>,
Daniel Vetter <daniel@...ll.ch>,
Michael Turquette <mturquette@...libre.com>,
Stephen Boyd <sboyd@...nel.org>,
Linux ARM <linux-arm-kernel@...ts.infradead.org>,
linux-kernel@...r.kernel.org, linux-spi@...r.kernel.org,
linux-stm32@...md-mailman.stormreply.com,
"open list:DRM PANEL DRIVERS" <dri-devel@...ts.freedesktop.org>,
linux-clk <linux-clk@...r.kernel.org>
Subject: Re: [PATCH v4 3/8] spi: stm32: Add 'SPI_SIMPLEX_RX', 'SPI_3WIRE_RX'
support for stm32f4
hi Mark,
Thanks for reviewing.
On Fri, May 22, 2020 at 7:36 PM Mark Brown <broonie@...nel.org> wrote:
>
> On Mon, May 18, 2020 at 07:09:20PM +0800, dillon.minfei@...il.com wrote:
>
> > 2, use stm32 spi's "In full-duplex (BIDIMODE=0 and RXONLY=0)", as tx_buf is
> > null, we must add dummy data sent out before read data.
> > so, add stm32f4_spi_tx_dummy() to handle this situation.
>
> There are flags SPI_CONTROLLER_MUST_TX and SPI_CONTROLLER_MUST_RX flags
> that the driver can set if it needs to, no need to open code this in the
> driver.
Yes, after check SPI_CONTROLLER_MUST_TX in drivers/spi/spi.c , it's
indeed to meet
this situation, i will try it and sumbmit a new patch.
thanks.
best regards
Dillon
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