From 3cc3eb1148e4b2dfabf7a1dcf36fd8be1331ca95 Mon Sep 17 00:00:00 2001 From: Jeff Garzik Date: Wed, 26 Sep 2007 00:02:41 -0400 Subject: [PATCH] [libata] AHCI: enable AHCI mode, before using AHCI reset AHCI spec says host-reset bit may only be set when the ahci-enable bit is also set. Noticed by Peer Chen Signed-off-by: Jeff Garzik --- drivers/ata/ahci.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 9f3c591c7214..b615390b6b8a 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -827,8 +827,14 @@ static int ahci_reset_controller(struct ata_host *host) void __iomem *mmio = host->iomap[AHCI_PCI_BAR]; u32 tmp; - /* global controller reset */ + /* 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)) + writel(tmp | HOST_AHCI_EN, mmio + HOST_CTL); + + /* global controller reset */ if ((tmp & HOST_RESET) == 0) { writel(tmp | HOST_RESET, mmio + HOST_CTL); readl(mmio + HOST_CTL); /* flush */ -- 2.20.1