[PATCH] spi: atmel: Prevent false timeouts on long transfers

[Miquel Raynal]

Hi Mark,

broonie at kernel.org wrote on Fri, 16 Jun 2023 15:20:27 +0100:

> On Fri, Jun 16, 2023 at 04:12:25PM +0200, Miquel Raynal wrote:
> 
> > -#define SPI_DMA_TIMEOUT		(msecs_to_jiffies(1000))
> > +#define SPI_DMA_MIN_TIMEOUT	(msecs_to_jiffies(1000))
> > +#define SPI_DMA_TIMEOUT_PER_10K	(msecs_to_jiffies(4))  
> 
> Given that we know the bus speed can't we just calculate this like other
> drivers do (we should probably add a helper TBH)?

I agree we should probably have some kind of easy-to-use helper to
derive a decent timeout value. How do sound the heuristics
proposed here to you ? That would be:

	timeout = 1s + 4ms/10k

Thanks,
Miquèl