Re: [PATCH 4/4] spi: s3c64xx: Fix large transfers with DMA

From: Vincent Whitchurch
Date: Mon Sep 26 2022 - 11:10:03 EST


On Mon, Sep 19, 2022 at 03:38:29PM +0100, Mark Brown wrote:
> On Fri, Sep 16, 2022 at 01:39:51PM +0200, Vincent Whitchurch wrote:
> > The COUNT_VALUE in the PACKET_CNT register is 16-bit so the maximum
> > value is 65535. Asking the driver to transfer a larger size currently
> > leads to the DMA transfer timing out. Fix this by splitting the
> > transfer as needed.
>
> The driver should just set max_transfer_size and let the core
> handle this.

Hmm, AFAICS, the core doesn't actually do anything with
max_transfer_size? It's only used from spi-mem and a handful of other
clients via spi_max_transfer_size().