Re: [PATCH 4/4] Revert "platform/chrome: cros_ec_spi: Transfer messages at high priority"

From: Doug Anderson
Date: Mon May 13 2019 - 16:23:13 EST


On Mon, May 13, 2019 at 9:47 AM, Mark Brown <broonie@xxxxxxxxxx> wrote:

> On Mon, May 13, 2019 at 09:03:28AM -0700, Doug Anderson wrote:
> > On Mon, May 13, 2019 at 9:02 AM Mark Brown <broonie@xxxxxxxxxx> wrote:
> > > I'm not saying the other changes aren't helping, I'm saying that it's
> > > not clear that this revert is improving things.
> > If I add a call to force the pumping to happen on the SPI thread then
> > the commit I'm reverting here is useless though, isn't it?
> Well, I'm not convinced that that change is ideal anyway and it does
> leave you vulnerable to further changes in the SPI core pushing things
> out to calling context which feels like it isn't going to be helping
> robustness.

OK. Here's my plan: in v2 I've still included this revert and you can
see how things look. If you hate it as much as you think you will
then let me know and I'll send a v3 that avoids to forcing and re-adds
the realtime thread to cros_ec.

One note just so you're aware: For my particular device I'm not nearly
as concerned with latency / throughput as I am concerned with
transfers not getting interrupted once started. I've added this
explicitly in the commit message now, too. :-)