Hello.
Akira Iguchi wrote:
Workaround for errata A308: turn down the UDMA mode and retry
the DMA command when the data lost condition is detected.
Signed-off-by: Kou Ishizaki <[EMAIL PROTECTED]>
Signed-off-by: Akira Iguchi <[EMAIL PROTECTED]>
---
diff -purN -X linux-powerpc-git/Documentation/dontdiff
linux-powerpc-git/drivers/ide/pci/scc_pata.c
linux-powerpc-git.mod/drivers/ide/pci/scc_pata.c
--- linux-powerpc-git/drivers/ide/pci/scc_pata.c 2007-05-22
13:08:32.000000000 +0900
+++ linux-powerpc-git.mod/drivers/ide/pci/scc_pata.c 2007-07-10
17:10:10.000000000 +0900
@@ -278,6 +278,13 @@ static int scc_tune_chipset(ide_drive_t
offset = 0; /* 100MHz */
}
+ /* errata A308 workaround: limit non ide_disk drive to UDMA4 */
+ if (drive->media != ide_disk && speed > XFER_UDMA_4) {
+ printk(KERN_INFO "%s: limit drive(media=%x) to UDMA4\n",
+ SCC_PATA_NAME, drive->media);
+ speed = XFER_UDMA_4;
+ }
+
The same comment as Alan had to the libata driver: use the new
udma_filter() method for this.
@@ -401,6 +408,33 @@ static int scc_ide_dma_end(ide_drive_t *
ide_hwif_t *hwif = HWIF(drive);
unsigned long intsts_port = hwif->dma_base + 0x014;
u32 reg;
+ int dma_stat, data_lost = 0;
+ static int retry = 0;
+
+ /* errata A308 workaround: Step5 (check data lost) */
+ /* 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: data lost occurred. (ACTEINT==0,
retry:%d)\n",
Should be "data loss" -- if this indeed means that data was lost *on the
media*.
+ drive->name, retry);
+ data_lost = 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 +503,25 @@ static int scc_ide_dma_end(ide_drive_t *
break;
}
- return __ide_dma_end(drive);
+ dma_stat = __ide_dma_end(drive);
+ if (data_lost)
+ 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);
+ ide_hwif_t *hwif = HWIF(drive);
+ 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 &&
Enclose bitwise AND expression into parens, please.
+ 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)
MBR, Sergei
-
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