Re: Bad reactions to QUEUE FULL

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

On Wed, 2003-04-30 at 00:02, Tim Pepper wrote:
> Anybody interested in having a look at this or is it a known issue?

Actually, I'd be most interested in knowing what the problem is that the
patch solves.

The "old" fields (and all inconsistently named) are designed to keep a
copy of the original command for when the actual command gets re-used. 
This re-use happens in the error handler (to get sense, send TURs etc)
and sometimes in the device drivers if they simulate ACA).  Everything
that replaces the command is supposed to copy the old one back after
it's finished using it.

However, QUEUE FULL is a status return, not a sense code, so any command
that gets QUEUE FULL should be an original command, and thus not need
the fields replacing.  Even more curious, if the command were replaced,
then more fields than just the data direction would need putting back.

A viable theory seems to be that the drivers (qlogic and emulex) change
the sc_data_direction field for their own purposes and forget to restore
it again.  I don't have the source, so I can't check this.

Does anyone have any other theories?

James