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Commit fae57d34 authored by Akira Iguchi's avatar Akira Iguchi Committed by Jeff Garzik
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pata_scc.c: Workaround for errata A308 



Workaround for errata A308: turn down the UDMA mode and retry
the DMA command when the data lost condition is detected.

Signed-off-by: default avatarKou Ishizaki <kou.ishizaki@toshiba.co.jp>
Signed-off-by: default avatarAkira Iguchi <akira2.iguchi@toshiba.co.jp>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent a520f261

drivers/ata/pata_scc.c

+35 −15
Original line number Diff line number Diff line
@@ -238,6 +238,12 @@ static void scc_set_dmamode (struct ata_port *ap, struct ata_device *adev) 
	else

		offset = 0;	/* 100MHz */



	/* errata A308 workaround: limit ATAPI UDMA mode to UDMA4 */

	if (adev->class == ATA_DEV_ATAPI && speed > XFER_UDMA_4) {

		printk(KERN_INFO "%s: limit ATAPI UDMA to UDMA4\n", DRV_NAME);

		speed = XFER_UDMA_4;

	}



	if (speed >= XFER_UDMA_0)

		idx = speed - XFER_UDMA_0;

	else
@@ -724,22 +730,36 @@ static void scc_bmdma_stop (struct ata_queued_cmd *qc) 


static u8 scc_bmdma_status (struct ata_port *ap)

{

	u8 host_stat;

	void __iomem *mmio = ap->ioaddr.bmdma_addr;

	u8 host_stat = in_be32(mmio + SCC_DMA_STATUS);

	u32 int_status = in_be32(mmio + SCC_DMA_INTST);

	struct ata_queued_cmd *qc = ata_qc_from_tag(ap, ap->active_tag);

	static int retry = 0;



	host_stat = in_be32(mmio + SCC_DMA_STATUS);

	/* return if IOS_SS is cleared */

	if (!(in_be32(mmio + SCC_DMA_CMD) & ATA_DMA_START))

		return host_stat;



	/* Workaround for PTERADD: emulate DMA_INTR when

	 * - IDE_STATUS[ERR] = 1

	 * - INT_STATUS[INTRQ] = 1

	 * - DMA_STATUS[IORACTA] = 1

	 */

	if (!(host_stat & ATA_DMA_INTR)) {

		u32 int_status = in_be32(mmio + SCC_DMA_INTST);

		if (ata_altstatus(ap) & ATA_ERR &&

		    int_status & INTSTS_INTRQ &&

		    host_stat & ATA_DMA_ACTIVE)

	/* errata A252,A308 workaround: Step4 */

	if (ata_altstatus(ap) & ATA_ERR && int_status & INTSTS_INTRQ)

		return (host_stat | ATA_DMA_INTR);



	/* errata A308 workaround Step5 */

	if (int_status & INTSTS_IOIRQS) {

		host_stat |= ATA_DMA_INTR;



		/* We don't check ATAPI DMA because it is limited to UDMA4 */

		if ((qc->tf.protocol == ATA_PROT_DMA &&

		     qc->dev->xfer_mode > XFER_UDMA_4)) {

			if (!(int_status & INTSTS_ACTEINT)) {

				printk(KERN_WARNING "ata%u: data lost occurred. (ACTEINT==0, retry:%d)\n",

				       ap->print_id, retry);

				host_stat |= ATA_DMA_ERR;

				if (retry++)

					ap->udma_mask >>= 1;

			} else

				retry = 0;

		}

	}



	return host_stat;