Alan Cox wrote:
> +/**
> + *   sl82c105_qc_defer       -       implement serialization
> + *   @qc: command
> + *
> + *   We must issue one command per host not per channel because
> + *   of the reset bug.
> + *
> + *   Q: is the scsi host lock sufficient ?
> + */
> +
> +static int sl82c105_qc_defer(struct ata_queued_cmd *qc)
> +{
> +     struct ata_host *host = qc->ap->host;
> +     int rc;
> +
> +     /* First apply the usual rules */       
> +     rc = ata_std_qc_defer(qc);
> +     if (rc != 0)
> +             return rc;
> +
> +     /* Now apply serialization rules. Only allow a command if the
> +        other channel state machine is idle */
> +     if (host->port[0] != qc->ap && 
> +                     host->port[0]->hsm_task_state != HSM_ST_IDLE)
> +             return  ATA_DEFER_PORT;
> +     if (host->port[1] != qc->ap && 
> +                     host->port[1]->hsm_task_state != HSM_ST_IDLE)
> +             return  ATA_DEFER_PORT;
> +     return 0;
> +}

hsm_task_state is not necessarily protected by host lock.  I think
testing ap->qc_active would be better.

-- 
tejun
-
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to