Re: [PATCH 1/2] scsi: Add scsi_device max_cmd_len

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

James Bottomley wrote:
> On Tue, 2006-03-28 at 16:17 -0600, Brian King wrote:
>> Add a max_cmd_len field to the scsi_device struct
>> to allow for per device limits of allowable command
>> lengths. This will be used by libata, which is currently
>> using the max_cmd_len field in the scsi_host struct,
>> which doesn't work for attaching libata controlled
>> SATA devices to SAS HBAs.
> 
> This really doesn't look correct.  What you want is a sata transport
> class with a max command length in the host device.

My direction at this point has been to move away from
the virtual scsi host device for SATA devices attached
to SAS HBAs. This seemed to me to be the clearest implementation.
Then you have 1 SAS HBA = 1 struct scsi_host, no matter
how many SATA devices are attached underneath it either
via direct attach or via an expander.


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