Re: [PATCH 3/8] spi: dw-dma: Configure the DMA channels in dma_setup

From: Andy Shevchenko
Date: Fri Jul 31 2020 - 05:16:43 EST


On Fri, Jul 31, 2020 at 10:59:48AM +0300, Serge Semin wrote:
> Mainly this is a preparation patch before adding one-by-one DMA SG entries
> transmission. But logically the Tx and Rx DMA channels setup should be
> performed in the dma_setup() callback anyway. So let's move the DMA slave
> channels src/dst burst lengths, address and address width configuration to
> the DMA setup stage. While at it make sure the return value of the
> dmaengine_slave_config() method is checked. It has been unnecessary in
> case if Dw DMAC is utilized as a DMA engine, since its device_config()
> callback always returns zero (though it might change in future). But since
> DW APB SSI driver now supports any DMA back-end we must make sure the
> DMA device configuration has been successful before proceeding with
> further setups.

...

> + if (!xfer->rx_buf)
> + return NULL;

...

> + if (xfer->rx_buf) {

> + }

This looks like a separate change to drop one of them and not hide in the next patch.

--
With Best Regards,
Andy Shevchenko