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 <kou.ishizaki@xxxxxxxxxxxxx>
Signed-off-by: Akira Iguchi <akira2.iguchi@xxxxxxxxxxxxx>
---
diff -purN -X linux-powerpc-git/Documentation/dontdiff linux-powerpc-git/drivers/ata/pata_scc.c linux-powerpc-git.mod/drivers/ata/pata_scc.c
--- linux-powerpc-git/drivers/ata/pata_scc.c 2007-06-11 12:03:24.000000000 +0900
+++ linux-powerpc-git.mod/drivers/ata/pata_scc.c 2007-07-10 17:13:01.000000000 +0900
@@ -238,6 +238,12 @@ static void scc_set_dmamode (struct ata_
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_q
static u8 scc_bmdma_status (struct ata_port *ap)
{
- u8 host_stat;
void __iomem *mmio = ap->ioaddr.bmdma_addr;
-
- host_stat = in_be32(mmio + SCC_DMA_STATUS);
-
- /* 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)
- host_stat |= ATA_DMA_INTR;
+ 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;
+
+ /* return if IOS_SS is cleared */
+ if (!(in_be32(mmio + SCC_DMA_CMD) & ATA_DMA_START))
+ return host_stat;
+
+ /* 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;
-
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