Re: [PATCH] hptiop: HighPoint RocketRAID 3xxx controller driver

On Sun, 2006-06-11 at 19:18 +0800, HighPoint Linux Team wrote:
dprintk("hptiop_queuecmd : no free req\n");
- scp->result = DID_BUS_BUSY << 16;
+ scp->result = SCSI_MLQUEUE_HOST_BUSY;
goto cmd_done;

As jeff said, this needs to become a return SCSI_MLQUEUE_HOST_BUSY.

On Sunday 11 June 2006 05:07 pm, HighPoint Linux Team wrote:

host->can_queue = le32_to_cpu(iop_config.max_requests);
host->cmd_per_lun = le32_to_cpu(iop_config.max_requests);

You might want to think about adjusting this. For the single LUN case,
it's fine. For the multi-lun case it may allow commands to a single LUN
to starve everything else.

There will be no multi-lun support for the controller so this is not
an issue.

Sorry, a mistake. Multi-lun is supported.
Should host->can_queue be set to (cmd_per_lun * max_lun) ?

It depends on how the controller behaves. Setting can_queue and
cmd_per_lun tends to work for most SCSI controllers because the actual
scsi devices have queue depths << this number. If your controller will
behave like this (i.e. will not allow the internal queue for a single
lun to fill up to this depth) then you can keep this setting (although,
again, since this is probably fixed by the firmware, you want to set
cmd_per_lun to this value to avoid excessive QUEUE_FULL returns). If
the controller will happily load all the available slots up for a single
lun, then you might want to think about reducing cmd_per_lun to some
fraction of can_queue (you could even set it to can_queue - 2 like the
3ware controller).

Most of the other actual raid controllers seem to have much smaller
per-lun queues, so they mainly set smaller, fixed size values for
cmd_per_lun.

James


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