Commit 78d5ae39 authored by Shane Huang's avatar Shane Huang Committed by Jeff Garzik
Browse files

ahci: kill @force_restart and refine CLO for ahci_kick_engine() 



This patch refines ahci_kick_engine() after discussion with Tejun about
FBS(FIS-based switching) support preparation:
a. Kill @force_restart and always kick the engine. The only case where
   @force_restart is zero is when it's called from ahci_p5wdh_hardreset()
   Actually at that point, BSY is pretty much guaranteed to be set.
b. If PMP is attached, ignore busy and always do CLO. (AHCI-1.3 9.2)

Signed-off-by: default avatarShane Huang <shane.huang@amd.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent 02cb009b

drivers/ata/ahci.c

+10 −12
Original line number Diff line number Diff line
@@ -1634,7 +1634,7 @@ static void ahci_fill_cmd_slot(struct ahci_port_priv *pp, unsigned int tag, 
	pp->cmd_slot[tag].tbl_addr_hi = cpu_to_le32((cmd_tbl_dma >> 16) >> 16);

}



static int ahci_kick_engine(struct ata_port *ap, int force_restart)

static int ahci_kick_engine(struct ata_port *ap)

{

	void __iomem *port_mmio = ahci_port_base(ap);

	struct ahci_host_priv *hpriv = ap->host->private_data;
@@ -1642,18 +1642,16 @@ static int ahci_kick_engine(struct ata_port *ap, int force_restart) 
	u32 tmp;

	int busy, rc;



	/* do we need to kick the port? */

	busy = status & (ATA_BUSY | ATA_DRQ);

	if (!busy && !force_restart)

		return 0;



	/* stop engine */

	rc = ahci_stop_engine(ap);

	if (rc)

		goto out_restart;



	/* need to do CLO? */

	if (!busy) {

	/* need to do CLO?

	 * always do CLO if PMP is attached (AHCI-1.3 9.2)

	 */

	busy = status & (ATA_BUSY | ATA_DRQ);

	if (!busy && !sata_pmp_attached(ap)) {

		rc = 0;

		goto out_restart;

	}
@@ -1701,7 +1699,7 @@ static int ahci_exec_polled_cmd(struct ata_port *ap, int pmp, 
		tmp = ata_wait_register(port_mmio + PORT_CMD_ISSUE, 0x1, 0x1,

					1, timeout_msec);

		if (tmp & 0x1) {

			ahci_kick_engine(ap, 1);

			ahci_kick_engine(ap);

			return -EBUSY;

		}

	} else
@@ -1724,7 +1722,7 @@ static int ahci_do_softreset(struct ata_link *link, unsigned int *class, 
	DPRINTK("ENTER\n");



	/* prepare for SRST (AHCI-1.1 10.4.1) */

	rc = ahci_kick_engine(ap, 1);

	rc = ahci_kick_engine(ap);

	if (rc && rc != -EOPNOTSUPP)

		ata_link_printk(link, KERN_WARNING,

				"failed to reset engine (errno=%d)\n", rc);
@@ -1940,7 +1938,7 @@ static int ahci_p5wdh_hardreset(struct ata_link *link, unsigned int *class, 
		rc = ata_wait_after_reset(link, jiffies + 2 * HZ,

					  ahci_check_ready);

		if (rc)

			ahci_kick_engine(ap, 0);

			ahci_kick_engine(ap);

	}

	return rc;

}
@@ -2321,7 +2319,7 @@ static void ahci_post_internal_cmd(struct ata_queued_cmd *qc) 


	/* make DMA engine forget about the failed command */

	if (qc->flags & ATA_QCFLAG_FAILED)

		ahci_kick_engine(ap, 1);

		ahci_kick_engine(ap);

}



static void ahci_pmp_attach(struct ata_port *ap)

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