Hello, Jens.
Jens Axboe wrote:
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 2733b0c..04f7a8d 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -742,7 +742,11 @@ static struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev,
> {
> struct ata_queued_cmd *qc;
>
> - qc = ata_qc_new_init(dev);
> + if (cmd->request->tag != -1)
> + qc = ata_qc_new_init(dev, cmd->request->tag);
> + else
> + qc = ata_qc_new_init(dev, 0);
> +
> if (qc) {
> qc->scsicmd = cmd;
> qc->scsidone = done;
> @@ -1137,7 +1141,17 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
>
> depth = min(sdev->host->can_queue, ata_id_queue_depth(dev->id));
> depth = min(ATA_MAX_QUEUE - 1, depth);
> - scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
> +
> + /*
> + * If this device is behind a port multiplier, we have
> + * to share the tag map between all devices on that PMP.
> + * Set up the shared tag map here and we get automatic.
> + */
> + if (dev->link->ap->pmp_link)
> + scsi_init_shared_tag_map(sdev->host, ATA_MAX_QUEUE - 1);
> +
> + scsi_set_tag_type(sdev, MSG_SIMPLE_TAG);
> + scsi_activate_tcq(sdev, depth);
> }
I don't think this is quite correct. If a !NCQ device is behind PMP,
the queue won't be tagged and all requests for the device would get -1
blk tag which gets translated to 0 libata tag, which may be in use by
other NCQ or non-NCQ device behind the same PMP.
Thanks.
--
tejun
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