sata_mv: Prevent PIO commands to be defered too long if traffic in progress. (159a7ff7) · Commits · 戴 / test

drivers/ata/sata_mv.c

+27 −2

Original line number	Diff line number	Diff line
		@@ -1382,6 +1382,25 @@ static int mv_qc_defer(struct ata_queued_cmd *qc)
		*/
		if (pp->pp_flags & MV_PP_FLAG_DELAYED_EH)
		return ATA_DEFER_PORT;

		/* PIO commands need exclusive link: no other commands [DMA or PIO]
		* can run concurrently.
		* set excl_link when we want to send a PIO command in DMA mode
		* or a non-NCQ command in NCQ mode.
		* When we receive a command from that link, and there are no
		* outstanding commands, mark a flag to clear excl_link and let
		* the command go through.
		*/
		if (unlikely(ap->excl_link)) {
		if (link == ap->excl_link) {
		if (ap->nr_active_links)
		return ATA_DEFER_PORT;
		qc->flags \|= ATA_QCFLAG_CLEAR_EXCL;
		return 0;
		} else
		return ATA_DEFER_PORT;
		}

		/*
		* If the port is completely idle, then allow the new qc.
		*/
		@@ -1395,8 +1414,14 @@ static int mv_qc_defer(struct ata_queued_cmd *qc)
		* doesn't allow it.
		*/
		if ((pp->pp_flags & MV_PP_FLAG_EDMA_EN) &&
		(pp->pp_flags & MV_PP_FLAG_NCQ_EN) && ata_is_ncq(qc->tf.protocol))
		(pp->pp_flags & MV_PP_FLAG_NCQ_EN)) {
		if (ata_is_ncq(qc->tf.protocol))
		return 0;
		else {
		ap->excl_link = link;
		return ATA_DEFER_PORT;
		}
		}

		return ATA_DEFER_PORT;
		}