ATA_STD_QC_DEFER(9)                       libata Library                      ATA_STD_QC_DEFER(9)



NAME
       ata_std_qc_defer - Check whether a qc needs to be deferred

SYNOPSIS
       int ata_std_qc_defer(struct ata_queued_cmd * qc);

ARGUMENTS
       qc
           ATA command in question

DESCRIPTION
       Non-NCQ commands cannot run with any other command, NCQ or not. As upper layer only knows
       the queue depth, we are responsible for maintaining exclusion. This function checks
       whether a new command qc can be issued.

       LOCKING: spin_lock_irqsave(host lock)

RETURN
       ATA_DEFER_* if deferring is needed, 0 otherwise.

AUTHOR
       Jeff Garzik
           Author.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                       ATA_STD_QC_DEFER(9)