Re: [PATCH 08/13] i2c: nomadik: replace jiffies by ktime for FIFO flushing timeout

[Théo Lebrun]

Hello,

On Mon Feb 19, 2024 at 3:21 PM CET, Linus Walleij wrote:
> On Thu, Feb 15, 2024 at 5:52 PM Théo Lebrun <theo.lebrun@xxxxxxxxxxx> wrote:
>
> > The FIFO flush function uses a jiffies amount to detect timeouts as the
> > flushing is async. Replace with ktime to get more accurate precision
> > and support short timeouts.
> >
> > Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
>
> Excellent patch. Thanks.
> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Somewhat related to this patch: while writing it, I noticed the total
timeout of flush_i2c_fifo() is 10 times the timeout. Without this
series, this means 10*200ms of busywaiting!

If you have an opinion on a more sensible option for this I could add a
patch to my V2. I don't know enough to pick a sensible value.

I'm unsure if it makes sense that the timeout of flush_i2c_fifo() is a
multiple of the transfer timeout. Does it make sense that those two
timeouts are correlated?

Big thanks for your review,

--
Théo Lebrun, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com