SCSI command order issue

["Wang Yong Hong, Wilson" <dsiyhw@dsi.nus.edu.sg>]

Hello,

Here I ask one question about SCSI protocol. 

I traced the linux kernel source code about SCSI module. 

In SCSI module, every SCSI command block is assigned 
one unique serial number. However this number is only 
valid before the block is returned to the SCSI middle layer.

There is no mechanism of sequence control for SCSI.
What is your opinion about the SCSI block out of order 
when they return to upper layer ? What do your people 
think about this ?

Thanks 

Wilson