Re: [PATCH] spi: spi-sun6i: implement DMA-based transfer mode

[Chen-Yu Tsai <wens@xxxxxxxx>]

On Tue, Oct 20, 2020 at 1:43 AM Alexander Kochetkov <al.kochet@xxxxxxxxx> wrote:
>
>
>
> > 19 окт. 2020 г., в 11:21, Maxime Ripard <maxime@xxxxxxxxxx> 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@xxxxxxxxx>
> >
> > 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 Do you mean that A64 is obsolete or EOL product?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.

ChenYu