> Date: Tue, 15 Dec 2020 13:32:22 +0100
> From: Claudio Jeker <cje...@diehard.n-r-g.com>
>
> On Fri, Dec 11, 2020 at 07:07:56PM -0600, Scott Cheloha wrote:
> > Hi,
> >
> > I'd like to remove lbolt from the kernel. I think having it in the
> > kernel complicates otherwise simple code.
> >
> > We can start with sdmmc(4).
> >
> > The goal in sdmmc_io_function_enable() is calling sdmmc_io_function_ready()
> > up to six times and sleep 1 second between each attempt. Here's rewritten
> > code that does with without lbolt.
> >
> > ok?
> >
> > Index: sdmmc_io.c
> > ===================================================================
> > RCS file: /cvs/src/sys/dev/sdmmc/sdmmc_io.c,v
> > retrieving revision 1.41
> > diff -u -p -r1.41 sdmmc_io.c
> > --- sdmmc_io.c 31 Dec 2019 10:05:33 -0000 1.41
> > +++ sdmmc_io.c 12 Dec 2020 01:04:59 -0000
> > @@ -231,8 +231,8 @@ sdmmc_io_function_enable(struct sdmmc_fu
> > {
> > struct sdmmc_softc *sc = sf->sc;
> > struct sdmmc_function *sf0 = sc->sc_fn0;
> > + int chan, retry = 5;
> > u_int8_t rv;
> > - int retry = 5;
> >
> > rw_assert_wrlock(&sc->sc_lock);
> >
> > @@ -244,7 +244,7 @@ sdmmc_io_function_enable(struct sdmmc_fu
> > sdmmc_io_write_1(sf0, SD_IO_CCCR_FN_ENABLE, rv);
> >
> > while (!sdmmc_io_function_ready(sf) && retry-- > 0)
> > - tsleep_nsec(&lbolt, PPAUSE, "pause", INFSLP);
> > + tsleep_nsec(&chan, PPAUSE, "pause", SEC_TO_NSEC(1));
> > return (retry >= 0) ? 0 : ETIMEDOUT;
> > }
> >
>
> Why not use &retry as wait channel instead of adding a new variable
> chan? Result is the same. Would it make sense to allow NULL as wait
> channel to make the tsleep not wakeable. At least that could be used in a
> few places where timeouts are implemented with tsleep and would make the
> intent more obvious.
Or have an appropriately named global variable? Something like "int nowake"?
