ichsmb(4) and msleep()

[Yuri Pankov]

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