Date: Wed, 28 Aug 2019 16:34:47 +0300 From: Yuri Pankov <yuripv@yuripv.net> To: Warner Losh <imp@bsdimp.com> Cc: Hans Petter Selasky <hps@selasky.org>, FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: Re: ichsmb(4) and msleep() Message-ID: <4201916c-0f7f-0bf6-2d17-e9f6a1879ba7@yuripv.net> In-Reply-To: <CANCZdfpevZ2PyLa9yai6cA5JYgNybgyHp0=1=er%2BeuJGcu9hew@mail.gmail.com> References: <7dfebbd3-85d6-c7b7-b83b-fae8b644649e@yuripv.net> <478965aa-5256-e356-5339-de6fb82c3459@selasky.org> <63daa36a-5c22-6b08-3cd7-562fa961ab61@yuripv.net> <7f6de96d-8b56-e242-8950-04a20b197bce@selasky.org> <311a21e3-ed61-8679-b416-b2a4c255c6e7@yuripv.net> <1f91f7a6-050d-d690-d374-6b06950d2ce2@yuripv.net> <CANCZdfpevZ2PyLa9yai6cA5JYgNybgyHp0=1=er%2BeuJGcu9hew@mail.gmail.com>
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Warner Losh wrote: > On Wed, Aug 28, 2019, 7:01 AM Yuri Pankov <yuripv@yuripv.net> wrote: > >> Yuri Pankov wrote: >>> Hans Petter Selasky wrote: >>>> On 2019-08-28 11:44, Yuri Pankov wrote: >>>>> Hans Petter Selasky wrote: >>>>>> On 2019-08-28 11:07, Yuri Pankov wrote: >>>>>>> I have a "timed sleep before timers are working" panic in >> ichsmb_readb() >>>>>>> calling ichsmb_wait() which uses msleep(). That is trying to >>>>>>> jedec_dimm(4) module so it's trying to attach pretty early in boot. >>>>>>> What would be the correct replacement for msleep() here? >>>>>>> >>>>>> >>>>>> If you only need a sleep-delay, pause() is the right one. It handles >>>>>> cold-boot. >>>>> >>>>> I guess that won't work here as we need to be waked up by interrupt >>>>> handler on command completion, and pause() seems to sleep >>>>> unconditionally for the given time in 'cold' case (if I'm reading the >>>>> code correctly). >>>> >>>> If you are too early inside a SYSINIT() path, then you cannot use >>>> sleeping. You will have to use polling in a loop with a fixed DELAY() >> to >>>> know the timeout. >>> >>> Thanks for the help. >>> >>> Something like the following (it seems to work)? >> >> Here's a review with the nit you mentioned fixed, thanks! >> >> https://reviews.freebsd.org/D21452 > > > > What's the advantages of doing this instead of deferring attach until the > interrupts are running? None that I can think of, just going with what was suggested and seeing other drivers doing the same. Could you please name a driver that defers attach until !cold?
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