Re: [PATCH 1/1] scsi: Add allow_restart sysfs class attribute

[Brian King <brking@us.ibm.com>]

Stefan Richter wrote:
> Brian King wrote:
>> This is a resend of a patch I generated in response to an email sent
>> by Ruben Faelens <parasietje@gmail.com>. His original email to
>> linux-scsi requested a method in which he could spin down a scsi disk
>> when not in use and have the kernel automatically spin it back up when
>> an I/O was generated to the disk. The infrastructure to automatically
>> spin a disk up has been in the scsi error handler for some time now,
> 
> I am positively surprised that this code is actually already there --- I 
> didn't notice...
> 
>> but it is not enabled by default. This patch adds an sd sysfs attribute
>> which allows userspace to enable this behavior.
> 
> What is the reason that the code is not enabled by default? Are there 
> dependencies on command set or transport, or firmwares which won't react 
> properly?

There was concern when the patch went in that if it was enabled by default
it would break a bunch of USB devices.

http://marc.theaimsgroup.com/?l=linux-scsi&m=107702811830956&w=2


-- 
Brian King
eServer Storage I/O
IBM Linux Technology Center