Re: Possible bug in SCSI Kconfig

From: Fabio Comolli
Date: Wed Oct 22 2008 - 15:26:00 EST


Hi.

On Wed, Oct 22, 2008 at 9:05 PM, James Bottomley
<James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, 2008-10-22 at 18:29 +0200, Fabio Comolli wrote:
>> Hi.
>> In kernel 2.6.27.2 - drivers/scsi/Kconfig we have:
>>
>> config SCSI_WAIT_SCAN
>> tristate
>> default m
>> depends on SCSI
>> depends on MODULES
>>
>> The tristate field is empty. This has the effect that this option is
>> not visible in menuconfig and so it's always selected. The default is
>> "m" for all architectures and so this module is always compiled if
>> SCSI and MODULES are both enabled.
>>
>> I'm using a patch like this one:
>>
>> config SCSI_WAIT_SCAN
>> - tristate
>> + tristate "Wait until all the async scans are complete"
>> default m
>> depends on SCSI
>> depends on MODULES
>>
>> to get rid of that module.
>>
>> Of course, I have no idea if this is correct or the current behavior
>> is the expected one.
>
> The point of all of this is that if you enable async scanning, you need
> a method of waiting for the scans to complete, which is all this module
> does (you insert it and it doesn't come back from the insertion until
> all the pending async scans are complete). It's tristate because really
> it only makes sense to be M or N. The consensus is that, given async
> scanning is always an option, this function should always be built as a
> module *if* modules and SCSI are enabled ... because you might have a
> HBA module you enabled async scanning for and you need to wait.

OK, I see your point.

But in my case I have SCSI enabled only because it's SELECTed by ATA
(it's just a laptop) and I don't have any hba's and never will. So no
async scan.

Maybe this module should be enabled if async scan is.

>
> There's really not much point giving the user the choice, since this
> module is part of the initrd sequence ... it's not really anything a
> user would want to use stand alone, hence there's no point giving a
> choice about it.
>

I don't use initrd at all. I just noticed the existence of this module
while trying to have a non modular kernel. This failed because of
ipw2200 and after having enabled modules again I just found this
scsi_wait_scan.ko.

> James
>
>
>

Regards,
Fabio
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