On Fri, Feb 17, 2017 at 09:23:10AM +0100, Hannes Reinecke wrote:
> The mpt3sas driver requires a reserved command space to handle
> SCSI passthrough commands.
>
> Signed-off-by: Hannes Reinecke <hare@xxxxxxxx>
> ---
> drivers/scsi/mpt3sas/mpt3sas_base.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
> index e9470a3..97189ad 100644
> --- a/drivers/scsi/mpt3sas/mpt3sas_base.c
> +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
> @@ -2360,6 +2360,8 @@ struct scsiio_tracker *
> } else {
> u32 unique_tag = blk_mq_unique_tag(scmd->request);
> u16 tag = blk_mq_unique_tag_to_tag(unique_tag);
> +
> + WARN_ON(tag < ioc->shost->reserved_cmds);
> request = scsi_cmd_priv(scmd);
> smid = tag + 1;
> }
> @@ -3521,7 +3523,8 @@ void mpt3sas_base_clear_st(struct MPT3SAS_ADAPTER *ioc,
> /* set the scsi host can_queue depth
> * with some internal commands that could be outstanding
> */
> - ioc->shost->can_queue = ioc->scsiio_depth - INTERNAL_SCSIIO_CMDS_COUNT;
> + ioc->shost->reserved_cmds = INTERNAL_SCSIIO_CMDS_COUNT;
> + ioc->shost->can_queue = ioc->scsiio_depth - ioc->shost->reserved_cmds;
You're never allocating a reserved request. Just remove the number of
reserved cmds from can_queue and you can use them on your own.
So I don't think you'll actually need to use reserved request here,
but instead you should set up can_queue properly earlier in the series.
