From 837f5f8fb98d4357d49e9631c9ee2815f3c328ca Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 6 Feb 2008 15:13:51 +0900 Subject: [PATCH] ahci: fix CAP.NP and PI handling AHCI uses CAP.NP to indicate the number of ports and PI to tell which ports are enabled. The only requirement is that the number of ports indicated by CAP.NP should equal or be higher than the number of enabled ports in PI. CAP.NP and PI carry duplicate information and there have been some interesting cases. Some early AHCI controllers didn't set PI at all and just implement from port 0 to CAP.NP. An ICH8 board which wired four out of six available ports had 3 (4 ports) for CAP.NP and 0x33 for PI. While ESB2 has less bits set in PI than the value in CAP.NP. Till now, ahci driver assumed that PI is invalid if it doesn't match CAP.NP exactly. This violates AHCI standard and the driver ends up accessing unmimplemented ports on ESB2. This patch updates CAP.NP and PI handling such that PI can have less number of bits set than indicated in CAP.NP and the highest port is determined as the maximum port of what CAP.NP and PI indicate. Signed-off-by: Tejun Heo Cc: Jan Beulich Signed-off-by: Jeff Garzik --- drivers/ata/ahci.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 27c8d56111c2..29e71bddd6ff 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -679,24 +679,20 @@ static void ahci_save_initial_config(struct pci_dev *pdev, /* cross check port_map and cap.n_ports */ if (port_map) { - u32 tmp_port_map = port_map; - int n_ports = ahci_nr_ports(cap); + int map_ports = 0; - for (i = 0; i < AHCI_MAX_PORTS && n_ports; i++) { - if (tmp_port_map & (1 << i)) { - n_ports--; - tmp_port_map &= ~(1 << i); - } - } + for (i = 0; i < AHCI_MAX_PORTS; i++) + if (port_map & (1 << i)) + map_ports++; - /* If n_ports and port_map are inconsistent, whine and - * clear port_map and let it be generated from n_ports. + /* If PI has more ports than n_ports, whine, clear + * port_map and let it be generated from n_ports. */ - if (n_ports || tmp_port_map) { + if (map_ports > ahci_nr_ports(cap)) { dev_printk(KERN_WARNING, &pdev->dev, - "nr_ports (%u) and implemented port map " - "(0x%x) don't match, using nr_ports\n", - ahci_nr_ports(cap), port_map); + "implemented port map (0x%x) contains more " + "ports than nr_ports (%u), using nr_ports\n", + port_map, ahci_nr_ports(cap)); port_map = 0; } } @@ -2201,7 +2197,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) struct device *dev = &pdev->dev; struct ahci_host_priv *hpriv; struct ata_host *host; - int i, rc; + int n_ports, i, rc; VPRINTK("ENTER\n"); @@ -2255,7 +2251,14 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) if (hpriv->cap & HOST_CAP_PMP) pi.flags |= ATA_FLAG_PMP; - host = ata_host_alloc_pinfo(&pdev->dev, ppi, fls(hpriv->port_map)); + /* CAP.NP sometimes indicate the index of the last enabled + * port, at other times, that of the last possible port, so + * determining the maximum port number requires looking at + * both CAP.NP and port_map. + */ + n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map)); + + host = ata_host_alloc_pinfo(&pdev->dev, ppi, n_ports); if (!host) return -ENOMEM; host->iomap = pcim_iomap_table(pdev); -- 2.20.1