According to the description of section 5.2.2.1 and 10.1.2 of AHCI specification rev1_1/rev1_2, GHC.HR shall only be set to ¡®1¡¯ by software when GHC.AE is set to ¡®1¡¯. Signed-off-by: Peer Chen <peerchen@xxxxxxxxx> --- --- linux-2.6.23-rc7/drivers/ata/ahci.c.orig 2007-09-20 11:01:55.000000000 -0400 +++ linux-2.6.23-rc7/drivers/ata/ahci.c 2007-09-20 11:07:31.000000000 -0400 @@ -834,6 +834,10 @@ static int ahci_reset_controller(struct void __iomem *mmio = host->iomap[AHCI_PCI_BAR]; u32 tmp; + /* turn on AHCI mode before controller reset*/ + writel(HOST_AHCI_EN, mmio + HOST_CTL); + (void) readl(mmio + HOST_CTL); /* flush */ + /* global controller reset */ tmp = readl(mmio + HOST_CTL); if ((tmp & HOST_RESET) == 0) { - -------------- Peer Chen 2007-09-21 - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html