From b710a1f4b34438b624e9c6c2dc8bcf54b0b0ba27 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sat, 5 Jan 2008 23:11:57 +0900 Subject: [PATCH] ahci: factor out AHCI enabling and enable AHCI before reading CAP Factor out AHCI enabling into ahci_enable_ahci() and enabling AHCI before reading CAP in ahci_save_initial_config() as the spec requires enabling AHCI mode before accessing any other registers. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik --- drivers/ata/ahci.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 49761bc12cf2..6f089b899a1a 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -597,6 +597,20 @@ static inline void __iomem *ahci_port_base(struct ata_port *ap) return __ahci_port_base(ap->host, ap->port_no); } +static void ahci_enable_ahci(void __iomem *mmio) +{ + u32 tmp; + + /* turn on AHCI_EN */ + tmp = readl(mmio + HOST_CTL); + if (!(tmp & HOST_AHCI_EN)) { + tmp |= HOST_AHCI_EN; + writel(tmp, mmio + HOST_CTL); + tmp = readl(mmio + HOST_CTL); /* flush && sanity check */ + WARN_ON(!(tmp & HOST_AHCI_EN)); + } +} + /** * ahci_save_initial_config - Save and fixup initial config values * @pdev: target PCI device @@ -619,6 +633,9 @@ static void ahci_save_initial_config(struct pci_dev *pdev, u32 cap, port_map; int i; + /* make sure AHCI mode is enabled before accessing CAP */ + ahci_enable_ahci(mmio); + /* Values prefixed with saved_ are written back to host after * reset. Values without are used for driver operation. */ @@ -1043,13 +1060,10 @@ static int ahci_reset_controller(struct ata_host *host) /* we must be in AHCI mode, before using anything * AHCI-specific, such as HOST_RESET. */ - tmp = readl(mmio + HOST_CTL); - if (!(tmp & HOST_AHCI_EN)) { - tmp |= HOST_AHCI_EN; - writel(tmp, mmio + HOST_CTL); - } + ahci_enable_ahci(mmio); /* global controller reset */ + tmp = readl(mmio + HOST_CTL); if ((tmp & HOST_RESET) == 0) { writel(tmp | HOST_RESET, mmio + HOST_CTL); readl(mmio + HOST_CTL); /* flush */ @@ -1068,8 +1082,7 @@ static int ahci_reset_controller(struct ata_host *host) } /* turn on AHCI mode */ - writel(HOST_AHCI_EN, mmio + HOST_CTL); - (void) readl(mmio + HOST_CTL); /* flush */ + ahci_enable_ahci(mmio); /* some registers might be cleared on reset. restore initial values */ ahci_restore_initial_config(host); -- 2.20.1