Yes, SB600 SATA AHCI controller can only support single PRD data xfer less than 256 sectors. BRs, Henry Su AMD SRDC SW/Linux Group T (8621)61658067 -----Original Message----- From: Jeff Garzik [mailto:jeff@xxxxxxxxxx] Sent: Friday, February 29, 2008 4:44 AM To: linux-ide@xxxxxxxxxxxxxxx; Cai, Crane; Su, Henry; Huang, Shane Cc: LKML Subject: [PATCH RFC] ahci: fix SB600 h/w errata issue I haven't seen anyone work on the recent SB600 errata, where the hardware does not like 256-length PRD entries. Is this correct, AMD folks? It hurts performance on SB600, but it is more important to get a correct patch eliminating the data corruption/lockups, and then later on tune for performance. We simply limit each command to a maximum of 255 sectors, on SB600. Signed-off-by: Jeff Garzik <jgarzik@xxxxxxxxxx> --- drivers/ata/ahci.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 1db93b6..8a49835 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -186,6 +186,7 @@ enum { AHCI_HFLAG_NO_MSI = (1 << 5), /* no PCI MSI */ AHCI_HFLAG_NO_PMP = (1 << 6), /* no PMP */ AHCI_HFLAG_NO_HOTPLUG = (1 << 7), /* ignore PxSERR.DIAG.N */ + AHCI_HFLAG_SECT255 = (1 << 8), /* max 255 sectors */ /* ap->flags bits */ @@ -255,6 +256,7 @@ static void ahci_vt8251_error_handler(struct ata_port *ap); static void ahci_p5wdh_error_handler(struct ata_port *ap); static void ahci_post_internal_cmd(struct ata_queued_cmd *qc); static int ahci_port_resume(struct ata_port *ap); +static void ahci_dev_config(struct ata_device *dev); static unsigned int ahci_fill_sg(struct ata_queued_cmd *qc, void *cmd_tbl); static void ahci_fill_cmd_slot(struct ahci_port_priv *pp, unsigned int tag, u32 opts); @@ -294,6 +296,8 @@ static const struct ata_port_operations ahci_ops = { .check_altstatus = ahci_check_status, .dev_select = ata_noop_dev_select, + .dev_config = ahci_dev_config, + .tf_read = ahci_tf_read, .qc_defer = sata_pmp_qc_defer_cmd_switch, @@ -425,7 +429,7 @@ static const struct ata_port_info ahci_port_info[] = { /* board_ahci_sb600 */ { AHCI_HFLAGS (AHCI_HFLAG_IGN_SERR_INTERNAL | - AHCI_HFLAG_32BIT_ONLY | AHCI_HFLAG_NO_PMP), + AHCI_HFLAG_SECT255 | AHCI_HFLAG_NO_PMP), .flags = AHCI_FLAG_COMMON, .link_flags = AHCI_LFLAG_COMMON, .pio_mask = 0x1f, /* pio0-4 */ @@ -1176,6 +1180,14 @@ static void ahci_init_controller(struct ata_host *host) VPRINTK("HOST_CTL 0x%x\n", tmp); } +static void ahci_dev_config(struct ata_device *dev) +{ + struct ahci_host_priv *hpriv = dev->link->ap->host->private_data; + + if (hpriv->flags & AHCI_HFLAG_SECT255) + dev->max_sectors = 255; +} + static unsigned int ahci_dev_classify(struct ata_port *ap) { void __iomem *port_mmio = ahci_port_base(ap); -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
