Re: [PATCH] nfit: Continue init even if ARS commands are unimplemented

[Dan Williams]

Andrew, sorry, ignore this, I fumble fingered a ^R in bash and sent
this.  I'm going to include this in a pull request to Linus.

On Fri, Mar 4, 2016 at 4:46 PM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> From: Vishal Verma <vishal.l.verma@xxxxxxxxx>
>
> If firmware doesn't implement any of the ARS commands, take that to
> mean that ARS is unsupported, and continue to initialize regions without
> bad block lists. We cannot make the assumption that ARS commands will be
> unconditionally supported on all NVDIMMs.
>
> Reported-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
> Signed-off-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
> Acked-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
> Tested-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---
>  drivers/acpi/nfit.c |   15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
> index fb53db187854..35947ac87644 100644
> --- a/drivers/acpi/nfit.c
> +++ b/drivers/acpi/nfit.c
> @@ -1590,14 +1590,21 @@ static int acpi_nfit_find_poison(struct acpi_nfit_desc *acpi_desc,
>         start = ndr_desc->res->start;
>         len = ndr_desc->res->end - ndr_desc->res->start + 1;
>
> +       /*
> +        * If ARS is unimplemented, unsupported, or if the 'Persistent Memory
> +        * Scrub' flag in extended status is not set, skip this but continue
> +        * initialization
> +        */
>         rc = ars_get_cap(nd_desc, ars_cap, start, len);
> +       if (rc == -ENOTTY) {
> +               dev_dbg(acpi_desc->dev,
> +                       "Address Range Scrub is not implemented, won't create an error list\n");
> +               rc = 0;
> +               goto out;
> +       }
>         if (rc)
>                 goto out;
>
> -       /*
> -        * If ARS is unsupported, or if the 'Persistent Memory Scrub' flag in
> -        * extended status is not set, skip this but continue initialization
> -        */
>         if ((ars_cap->status & 0xffff) ||
>                 !(ars_cap->status >> 16 & ND_ARS_PERSISTENT)) {
>                 dev_warn(acpi_desc->dev,
>