Re: [PATCH v1 RFC 1/2] spi: introduce fallback to pio

Mark Brown
2020-06-15T14:36:26Z

[-- Attachment #1: Type: text/plain, Size: 736 bytes --]

On Mon, Jun 15, 2020 at 02:18:54PM +0000, Robin Gong wrote:
> On 2020/06/15 21:39 Mark Brown <broonie@kernel.org> wrote:
> > On Mon, Jun 15, 2020 at 01:35:01PM +0000, Robin Gong wrote:

> > > Then how about choosing specific error code for such dma not ready
> > > case where nothing went out on the bus neither?

> > Yes, that's what I suggested.

> Seems not easy to find a suitable error value, how about EBADR which
> sounds like no any available dma_async_tx_descriptor got by calling dmaengine_prep_slave_sg?

> #define EBADR 53 /* Invalid request descriptor */

We could also pass in a flag that could be set separately to the error
code to indicate that nothing had happened to the hardware yet.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]