Re: [PATCH] ahci: enable GHC.AE bit before set GHC.HR

Andrew Morton
2007-09-21T10:29:25Z

On Fri, 21 Sep 2007 13:28:01 +0800 "Peer Chen" <peerchen@gmail.com> wrote:

> 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__.

This text contained non-ascii garbage which came through as __1__.

I'll assume that you actually meant "1".

> --- 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) {
>

We don't normally do that (void) cast.