Re: [PATCH] spi: mediatek: Manually set dma_ops for spi_master device

From: Dmitry Torokhov
Date: Thu Jan 26 2017 - 12:27:36 EST

On Thu, Jan 26, 2017 at 9:07 AM, Mark Brown <broonie@xxxxxxxxxx> wrote:
> On Fri, Jan 27, 2017 at 12:52:15AM +0800, Daniel Kurtz wrote:
>> On Fri, Jan 27, 2017 at 12:35 AM, Dmitry Torokhov <dtor@xxxxxxxxxxxx> wrote:
>> > Nobody doing DMA likes unaligned buffers. In fact, memory used for DMA
>> > must be cacheline aligned, or you going to have trouble. What
>> > component supplies unaligned buffers to SPI core for transfers?
>> cros-ec-spi
> That needs fixing then - I keep thinking we should add a warning to the
> core for this, especially now we do DMA mapping in the core.

OTOH the full buffer used by cros ec *is* DMA-safe (allocated with
kmalloc), it is that cors ec uses it at offset while transferring data
piece by piece. Do we want to support this?