Hi Miquel,
On 08.08.2018 10:56, Miquel Raynal wrote:
Boris Brezillon <boris.brezil...@bootlin.com> wrote on Tue, 7 Aug 2018
15:28:02 +0200:
On Tue, 7 Aug 2018 14:16:52 +0200
Stefan Roese <s...@denx.de> wrote:
Some SPI controller do not support full-duplex SPI transfers. This patch
changes the SPI transfer into 2 separate transfers - or 1, if no data is
to transmitted.
With this change, no buffers need to be allocated anymore. We use the
TX and RX buffers that are passed to spi_mem_exec_op() directly.
Signed-off-by: Stefan Roese <s...@denx.de>
Suggested-by: Boris Brezillon <boris.brezil...@bootlin.com>
Cc: Miquel Raynal <miquel.ray...@bootlin.com>
Cc: Boris Brezillon <boris.brezil...@bootlin.com>
Cc: Jagan Teki <ja...@openedev.com>
Looks good overall, just a few comments (that you might chose to ignore
if you disagree).
Reviewed-by: Boris Brezillon <boris.brezil...@bootlin.com>
Sorry for being a bit late on the discussion, but while I do agree with
the change, I'm not sure about its implementation : I think SPI
controllers are supposed to be abstracted by the SPI layer.
Addressing the controller's limitations in the SPI-mem layer would
not be appropriate.
Would it be possible to adapt spi_xfer() to handle such case?
No, I don't think so. Its impossible to guess in the SPI driver layer,
which parts of the message are TX data and which are RX data. So this
message can't be split up into a half-duplex one here. This can only
be done in the driver which constructs the SPI messages.
Or did I miss something here?
Thanks,
Stefan
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