From 89dafa20f3daab5b3e0c13d0068a28e8e64e2102 Mon Sep 17 00:00:00 2001 From: xiangliang yu Date: Sun, 27 Oct 2013 08:03:04 -0400 Subject: [PATCH] ahci: disabled FBS prior to issuing software reset Tested with Marvell 88se9125, attached with one port mulitplier(5 ports) and one disk, we will get following boot log messages if using current code: ata8: SATA link up 6.0 Gbps (SStatus 133 SControl 330) ata8.15: Port Multiplier 1.2, 0x1b4b:0x9715 r160, 5 ports, feat 0x1/0x1f ahci 0000:03:00.0: FBS is enabled ata8.00: hard resetting link ata8.00: SATA link down (SStatus 0 SControl 330) ata8.01: hard resetting link ata8.01: SATA link down (SStatus 0 SControl 330) ata8.02: hard resetting link ata8.02: SATA link down (SStatus 0 SControl 330) ata8.03: hard resetting link ata8.03: SATA link up 6.0 Gbps (SStatus 133 SControl 133) ata8.04: hard resetting link ata8.04: failed to resume link (SControl 133) ata8.04: failed to read SCR 0 (Emask=0x40) ata8.04: failed to read SCR 0 (Emask=0x40) ata8.04: failed to read SCR 1 (Emask=0x40) ata8.04: failed to read SCR 0 (Emask=0x40) ata8.03: native sectors (2) is smaller than sectors (976773168) ata8.03: ATA-8: ST3500413AS, JC4B, max UDMA/133 ata8.03: 976773168 sectors, multi 0: LBA48 NCQ (depth 31/32) ata8.03: configured for UDMA/133 ata8.04: failed to IDENTIFY (I/O error, err_mask=0x100) ata8.15: hard resetting link ata8.15: SATA link up 6.0 Gbps (SStatus 133 SControl 330) ata8.15: Port Multiplier vendor mismatch '0x1b4b' != '0x133' ata8.15: PMP revalidation failed (errno=-19) ata8.15: hard resetting link ata8.15: SATA link up 6.0 Gbps (SStatus 133 SControl 330) ata8.15: Port Multiplier vendor mismatch '0x1b4b' != '0x133' ata8.15: PMP revalidation failed (errno=-19) ata8.15: limiting SATA link speed to 3.0 Gbps ata8.15: hard resetting link ata8.15: SATA link up 3.0 Gbps (SStatus 123 SControl 320) ata8.15: Port Multiplier vendor mismatch '0x1b4b' != '0x133' ata8.15: PMP revalidation failed (errno=-19) ata8.15: failed to recover PMP after 5 tries, giving up ata8.15: Port Multiplier detaching ata8.03: disabled ata8.00: disabled ata8: EH complete The reason is that current detection code doesn't follow AHCI spec: First,the port multiplier detection process look like this: ahci_hardreset(link, class, deadline) if (class == ATA_DEV_PMP) { sata_pmp_attach(dev) /* will enable FBS */ sata_pmp_init_links(ap, nr_ports); ata_for_each_link(link, ap, EDGE) { sata_std_hardreset(link, class, deadline); if (link_is_online) /* do soft reset */ ahci_softreset(link, class, deadline); } } But, according to chapter 9.3.9 in AHCI spec: Prior to issuing software reset, software shall clear PxCMD.ST to '0' and then clear PxFBS.EN to '0'. The patch test ok with kernel 3.11.1. tj: Patch white space contaminated, applied manually with trivial updates. Signed-off-by: Xiangliang Yu Signed-off-by: Tejun Heo Cc: stable@vger.kernel.org --- drivers/ata/libahci.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c index 7e2a1b38093e..6686dbec4440 100644 --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -1267,9 +1267,11 @@ int ahci_do_softreset(struct ata_link *link, unsigned int *class, { struct ata_port *ap = link->ap; struct ahci_host_priv *hpriv = ap->host->private_data; + struct ahci_port_priv *pp = ap->private_data; const char *reason = NULL; unsigned long now, msecs; struct ata_taskfile tf; + bool fbs_disabled = false; int rc; DPRINTK("ENTER\n"); @@ -1279,6 +1281,16 @@ int ahci_do_softreset(struct ata_link *link, unsigned int *class, if (rc && rc != -EOPNOTSUPP) ata_link_warn(link, "failed to reset engine (errno=%d)\n", rc); + /* + * According to AHCI-1.2 9.3.9: if FBS is enable, software shall + * clear PxFBS.EN to '0' prior to issuing software reset to devices + * that is attached to port multiplier. + */ + if (!ata_is_host_link(link) && pp->fbs_enabled) { + ahci_disable_fbs(ap); + fbs_disabled = true; + } + ata_tf_init(link->device, &tf); /* issue the first D2H Register FIS */ @@ -1319,6 +1331,10 @@ int ahci_do_softreset(struct ata_link *link, unsigned int *class, } else *class = ahci_dev_classify(ap); + /* re-enable FBS if disabled before */ + if (fbs_disabled) + ahci_enable_fbs(ap); + DPRINTK("EXIT, class=%u\n", *class); return 0; -- 2.39.5