RE: Transport affected timeouts...

James Bottomley
2004-04-21T19:21:54Z

On Wed, 2004-04-21 at 12:53, Smart, James wrote:
> Where do we go from here ?
>
> What we are doing in our driver is the following:
> - Cancel the mid-layer timeout
> - Set timeout to (cmd->timeout_per_command/HZ) + hba_offset
> - Start timer based on new timeout value

Well, this is unacceptable. Only the mid layer should be mucking with
mid-layer timers.

> Where hba_offset is: (2 * R_A_TOV) + administrative increment (default 0)
> Where R_A_TOV is the fabric-reported timeout. R_A_TOV is at least a round
> trip time, plus 2 times max delivery delay time within the fabric. (default
> 10 seconds). This value can change based on fabric reconfiguration or
> plugging the adapter into a differnet fabric.

I'm still not clear on what you're trying to achieve.

the scsi_host_self_blocked interface was created with reconfig events in
mind...it still won't stop in-progress timers, but I've been considering
adding that feature for things like FC lip events.

James