Re: Quick aic7xxx bug hunt...

[Jeff Garzik <jgarzik@pobox.com>]

Justin T. Gibbs wrote:
>>>For all of these delays, I'd be more than happy to make them all into
>>>sleeps if I can tell, from inside ahc_delay() if I'm in a context where
>>>it is safe to sleep.  On the other platforms that this core code runs on
>>>I'm usually not in a context where it is safe to sleep, so I don't want
>>>to switch to using a different driver primitive.
>>
>>For Linux it's unconditionally safe, and other platforms is sounds like
>>it's unconditionally not.  So, s/ahc_delay/ahc_sleep/ for the places I
>>pointed out, and just make ahc_delay==ahc_sleep on non-Linux platforms
>>(or any similarly-functioning solution)
> 
> 
> So you can sleep while in an interrupt context?  I didn't know that
> 2.5 had switched to using interrupt threads or some similar construct.


Of course not :)

ahc_reset
	aic7770_config -> can sleep
	ahc_pci_config -> can sleep
	ahc_shutdown -> can't sleep, whoops
	ahc_resume -> dead code
ahc_init
	aic7770_config -> can sleep
	ahc_pci_config -> can sleep
ahc_acquire_seeprom
	check_extport -> can sleep
	ahc_proc_write_seeprom -> can sleep

so, ahc_init and ahc_acquire_seeprom can s/ahc_delay/ahc_sleep/ safely.

Oh, and I found another bug:  never use check_region, it's inherently 
racy.  Use request_region and check its return value.	

Note I agree with a comment in the code, that wrapping SHT->detect() in 
io_request_lock is silly...  the comment describing the rationale in 
drivers/scsi/scsi.c is not really accurate...

	Jeff