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Commit 4ae41ff8 authored by Kou Ishizaki's avatar Kou Ishizaki Committed by Bartlomiej Zolnierkiewicz
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scc_pata.c: Workaround for errata A308 (take 2) 



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

take2:
udma_filter() hook is used to limit ATAPI UDMA mode.

Signed-off-by: default avatarKou Ishizaki <kou.ishizaki@toshiba.co.jp>
Signed-off-by: default avatarAkira Iguchi <akira2.iguchi@toshiba.co.jp>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
parent f644d47a

drivers/ide/pci/scc_pata.c

+54 −13
Original line number Diff line number Diff line
@@ -401,6 +401,33 @@ static int scc_ide_dma_end(ide_drive_t * drive) 
	ide_hwif_t *hwif = HWIF(drive);

	unsigned long intsts_port = hwif->dma_base + 0x014;

	u32 reg;

	int dma_stat, data_loss = 0;

	static int retry = 0;



	/* errata A308 workaround: Step5 (check data loss) */

	/* We don't check non ide_disk because it is limited to UDMA4 */

	if (!(in_be32((void __iomem *)IDE_ALTSTATUS_REG) & ERR_STAT) &&

	    drive->media == ide_disk && drive->current_speed > XFER_UDMA_4) {

		reg = in_be32((void __iomem *)intsts_port);

		if (!(reg & INTSTS_ACTEINT)) {

			printk(KERN_WARNING "%s: operation failed (transfer data loss)\n",

			       drive->name);

			data_loss = 1;

			if (retry++) {

				struct request *rq = HWGROUP(drive)->rq;

				int unit;

				/* ERROR_RESET and drive->crc_count are needed

				 * to reduce DMA transfer mode in retry process.

				 */

				if (rq)

					rq->errors |= ERROR_RESET;

				for (unit = 0; unit < MAX_DRIVES; unit++) {

					ide_drive_t *drive = &hwif->drives[unit];

					drive->crc_count++;

				}

			}

		}

	}



	while (1) {

		reg = in_be32((void __iomem *)intsts_port);
@@ -469,27 +496,25 @@ static int scc_ide_dma_end(ide_drive_t * drive) 
		break;

	}



	return __ide_dma_end(drive);

	dma_stat = __ide_dma_end(drive);

	if (data_loss)

		dma_stat |= 2; /* emulate DMA error (to retry command) */

	return dma_stat;

}



/* returns 1 if dma irq issued, 0 otherwise */

static int scc_dma_test_irq(ide_drive_t *drive)

{

	ide_hwif_t *hwif = HWIF(drive);

	u8 dma_stat		= hwif->INB(hwif->dma_status);

	u32 int_stat = in_be32((void __iomem *)hwif->dma_base + 0x014);



	/* return 1 if INTR asserted */

	if ((dma_stat & 4) == 4)

	/* SCC errata A252,A308 workaround: Step4 */

	if ((in_be32((void __iomem *)IDE_ALTSTATUS_REG) & ERR_STAT) &&

	    (int_stat & INTSTS_INTRQ))

		return 1;



	/* Workaround for PTERADD: emulate DMA_INTR when

	 * - IDE_STATUS[ERR] = 1

	 * - INT_STATUS[INTRQ] = 1

	 * - DMA_STATUS[IORACTA] = 1

	 */

	if (in_be32((void __iomem *)IDE_ALTSTATUS_REG) & ERR_STAT &&

	    in_be32((void __iomem *)(hwif->dma_base + 0x014)) & INTSTS_INTRQ &&

		dma_stat & 1)

	/* SCC errata A308 workaround: Step5 (polling IOIRQS) */

	if (int_stat & INTSTS_IOIRQS)

		return 1;



	if (!drive->waiting_for_dma)
@@ -498,6 +523,21 @@ static int scc_dma_test_irq(ide_drive_t *drive) 
	return 0;

}



static u8 scc_udma_filter(ide_drive_t *drive)

{

	ide_hwif_t *hwif = drive->hwif;

	u8 mask = hwif->ultra_mask;



	/* errata A308 workaround: limit non ide_disk drive to UDMA4 */

	if ((drive->media != ide_disk) && (mask & 0xE0)) {

		printk(KERN_INFO "%s: limit %s to UDMA4\n",

		       SCC_PATA_NAME, drive->name);

		mask = 0x1F;

	}



	return mask;

}



/**

 *	setup_mmio_scc	-	map CTRL/BMID region

 *	@dev: PCI device we are configuring
@@ -702,6 +742,7 @@ static void __devinit init_hwif_scc(ide_hwif_t *hwif) 
	hwif->tuneproc = scc_tuneproc;

	hwif->ide_dma_check = scc_config_drive_for_dma;

	hwif->ide_dma_test_irq = scc_dma_test_irq;

	hwif->udma_filter = scc_udma_filter;



	hwif->drives[0].autotune = IDE_TUNE_AUTO;

	hwif->drives[1].autotune = IDE_TUNE_AUTO;