Re: [PATCH] ahci: retry enabling AHCI a few times before spitting out WARN_ON()

[Tejun Heo <htejun@gmail.com>]

Volker Armin Hemmann wrote:
>  static void ahci_enable_ahci(void __iomem *mmio)
>  {
> +       int i;
>         u32 tmp;
> 
>         /* turn on AHCI_EN */
>         tmp = readl(mmio + HOST_CTL);
> -       if (!(tmp & HOST_AHCI_EN)) {
> +       if (tmp & HOST_AHCI_EN)
> +               return;
> +
> +       /* Some controllers need AHCI_EN to be written multiple times.
> +        * Try a few times before giving up.
> +        */
> +       for (i = 0; i < 5; i++) {
>                 tmp |= HOST_AHCI_EN;
>                 writel(tmp, mmio + HOST_CTL);
>                 tmp = readl(mmio + HOST_CTL);   /* flush && sanity check */
> -               WARN_ON(!(tmp & HOST_AHCI_EN));
> +               if (tmp & HOST_AHCI_EN)
> +                       return;
> +               msleep(10);
>         }
> +
> +       WARN_ON(1);
>  }

Heh... your patch is white-space broken.  Just save whole mail to a file 
and use filterdiff to extract patch.  Copy & pasting doesn't always work.

-- 
tejun