Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1230524 > unrolled thread

Re: spi-imx: wait_for_completion should timeout even in non-DMA transfer cases

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: spi-imx: wait_for_completion should timeout even in non-DMA  transfer cases Mark Brown <broonie@kernel.org> - 2015-09-22 19:30 +0200

#1230524 — Re: spi-imx: wait_for_completion should timeout even in non-DMA transfer cases

[Multipart message — attachments visible in raw view] — view raw

On Mon, Sep 21, 2015 at 11:08:55AM +0200, Jean-Michel Hautbois wrote:
> 2015-09-19 19:56 GMT+02:00 Mark Brown <broonie@kernel.org>:

> > A calculated timeout is probably best.

> Well, it depends...
> If you have a 20MHz clock, then you can transfer a byte in 4µs.
> As most of the time pio_transfer is used for 8 to 32 bytes max, it
> would be irrelevant to use such a small timeout.
> I can obviously do it, but not sure if using a small (say, 100ms)
> timeout would not be better.

You want a minimum threashold, yes, but you also need to be able toc ope
with larger transfers too so need to be able to raise that where
appropriate.

[toc] | [standalone]

Back to top | Article view | linux.kernel

csiph-web