From 7b6dbd6872ca1d0c03dc0e0a7108d79c8dafa793 Mon Sep 17 00:00:00 2001 From: Greg Felix Date: Thu, 28 Jul 2005 15:54:15 -0400 Subject: [PATCH] libata: Check PCI sub-class code before disabling AHCI This patch adds functionality to check the PCI sub-class code of an AHCI capable device before disabling AHCI. It fixes a bug where an ICH7 sata controller is being setup by the BIOS as sub-class 1 (ide) and the AHCI control registers weren't being initialized, thus causing an IO error in piix_disable_ahci(). Signed-off-by: Gregory Felix --- drivers/scsi/ata_piix.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/ata_piix.c b/drivers/scsi/ata_piix.c index 3be546439252..a2cfade2c1c6 100644 --- a/drivers/scsi/ata_piix.c +++ b/drivers/scsi/ata_piix.c @@ -38,6 +38,7 @@ enum { PIIX_IOCFG = 0x54, /* IDE I/O configuration register */ ICH5_PMR = 0x90, /* port mapping register */ ICH5_PCS = 0x92, /* port control and status */ + PIIX_SCC = 0x0A, /* sub-class code register */ PIIX_FLAG_AHCI = (1 << 28), /* AHCI possible */ PIIX_FLAG_CHECKINTR = (1 << 29), /* make sure PCI INTx enabled */ @@ -62,6 +63,8 @@ enum { ich6_sata_rm = 4, ich7_sata = 5, esb2_sata = 6, + + PIIX_AHCI_DEVICE = 6, }; static int piix_init_one (struct pci_dev *pdev, @@ -574,11 +577,11 @@ static int piix_disable_ahci(struct pci_dev *pdev) addr = pci_resource_start(pdev, AHCI_PCI_BAR); if (!addr || !pci_resource_len(pdev, AHCI_PCI_BAR)) return 0; - + mmio = ioremap(addr, 64); if (!mmio) return -ENOMEM; - + tmp = readl(mmio + AHCI_GLOBAL_CTL); if (tmp & AHCI_ENABLE) { tmp &= ~AHCI_ENABLE; @@ -588,7 +591,7 @@ static int piix_disable_ahci(struct pci_dev *pdev) if (tmp & AHCI_ENABLE) rc = -EIO; } - + iounmap(mmio); return rc; } @@ -626,9 +629,13 @@ static int piix_init_one (struct pci_dev *pdev, const struct pci_device_id *ent) port_info[1] = NULL; if (port_info[0]->host_flags & PIIX_FLAG_AHCI) { - int rc = piix_disable_ahci(pdev); - if (rc) - return rc; + u8 tmp; + pci_read_config_byte(pdev, PIIX_SCC, &tmp); + if (tmp == PIIX_AHCI_DEVICE) { + int rc = piix_disable_ahci(pdev); + if (rc) + return rc; + } } if (port_info[0]->host_flags & PIIX_FLAG_COMBINED) { -- 2.20.1