Re: Warning: about not setting max_sectors

[James Bottomley <James.Bottomley@steeleye.com>]

hch@infradead.org said:
> I added this intentionally.  The default is set in scsi_register_host
> which is an obsolete interface.  This warning reminds driver writers
> to set the value explicitly, with scsi_add_host & friends they won't
> get a default anymore. 

I don't think that's the correct behaviour.  The parameter is labelled as 
optional (and clearly should be for drivers that have no hard transfer limit).

The blk_queue_max_sectors() clearly should be initialised with the device in 
mind.  We have this limit coming at us from two directions: the driver (if it 
imposes such a limit) and the device (e.g. a SCSI-1 device only does read 6 
and thus 256 is the maximum etc.)

we should probably take the lowest of the scsi-1 minimum and the HBA if it 
exists in scsi_initialize_queue and readjust it when we've decided on the 
capabilities of the device.

In any event, moving the zero check for shpnt->max_sectors to 
scsi_initialize_queue would fix the loss of scsi_add_host, wouldn't it?

James