diff options
| author | Tejun Heo <htejun@gmail.com> | 2006-11-02 12:17:23 +0900 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2006-12-01 22:41:31 -0500 |
| commit | 98fa4b60c673526fdd478d9719e41cd9e2b84986 (patch) | |
| tree | 696cb1f0d19bbda6dc9030eb11e4b2754472dfaa /drivers/ata/ahci.c | |
| parent | ada406c8246b0792afe4d7f8ae7606093052de87 (diff) | |
[PATCH] ahci: preserve PORTS_IMPL over host resets
Instead of writing 0xf blindly, preserve the content of write-once
PORTS_IMPL register over host resets.
This patch is taken from Jeff Garzik's AHCI init update patch.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/ata/ahci.c')
| -rw-r--r-- | drivers/ata/ahci.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index bc6599e4f47..f2277be70c0 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -421,6 +421,11 @@ static struct pci_driver ahci_pci_driver = { }; +static inline int ahci_nr_ports(u32 cap) +{ + return (cap & 0x1f) + 1; +} + static inline unsigned long ahci_port_base_ul (unsigned long base, unsigned int port) { return base + 0x100 + (port * 0x80); @@ -630,11 +635,12 @@ static int ahci_deinit_port(void __iomem *port_mmio, u32 cap, const char **emsg) static int ahci_reset_controller(void __iomem *mmio, struct pci_dev *pdev) { - u32 cap_save, tmp; + u32 cap_save, impl_save, tmp; cap_save = readl(mmio + HOST_CAP); cap_save &= ( (1<<28) | (1<<17) ); cap_save |= (1 << 27); + impl_save = readl(mmio + HOST_PORTS_IMPL); /* global controller reset */ tmp = readl(mmio + HOST_CTL); @@ -655,10 +661,21 @@ static int ahci_reset_controller(void __iomem *mmio, struct pci_dev *pdev) return -EIO; } + /* turn on AHCI mode */ writel(HOST_AHCI_EN, mmio + HOST_CTL); (void) readl(mmio + HOST_CTL); /* flush */ + + /* These write-once registers are normally cleared on reset. + * Restore BIOS values... which we HOPE were present before + * reset. + */ + if (!impl_save) { + impl_save = (1 << ahci_nr_ports(cap_save)) - 1; + dev_printk(KERN_WARNING, &pdev->dev, + "PORTS_IMPL is zero, forcing 0x%x\n", impl_save); + } writel(cap_save, mmio + HOST_CAP); - writel(0xf, mmio + HOST_PORTS_IMPL); + writel(impl_save, mmio + HOST_PORTS_IMPL); (void) readl(mmio + HOST_PORTS_IMPL); /* flush */ if (pdev->vendor == PCI_VENDOR_ID_INTEL) { @@ -1467,7 +1484,7 @@ static int ahci_host_init(struct ata_probe_ent *probe_ent) hpriv->cap = readl(mmio + HOST_CAP); hpriv->port_map = readl(mmio + HOST_PORTS_IMPL); - probe_ent->n_ports = (hpriv->cap & 0x1f) + 1; + probe_ent->n_ports = ahci_nr_ports(hpriv->cap); VPRINTK("cap 0x%x port_map 0x%x n_ports %d\n", hpriv->cap, hpriv->port_map, probe_ent->n_ports); |