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

[Andrew Morton <akpm@linux-foundation.org>]

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.