[Nouveau] [PATCH 5/8] acpi: Check returned object type by Optimus _DSM locally

[Ilia Mirkin]

On Mon, May 25, 2015 at 6:22 PM, Pierre Moreau <pierre.morrow at free.fr> wrote:
> Most _DSM will return an integer value of 0x80000002 when given an unknown
> UUID, revision ID or function ID. Checking locally allows us to differentiate
> that case from other ACPI errors, and to not report a "failed to evaluate _DSM"
> if 0x80000002 is returned which was confusing.
>
> Signed-off-by: Pierre Moreau <pierre.morrow at free.fr>
> ---
>  drm/nouveau/nouveau_acpi.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drm/nouveau/nouveau_acpi.c b/drm/nouveau/nouveau_acpi.c
> index 073f7d7..7aeaf7d 100644
> --- a/drm/nouveau/nouveau_acpi.c
> +++ b/drm/nouveau/nouveau_acpi.c
> @@ -88,12 +88,12 @@ static int nouveau_evaluate_optimus_dsm(acpi_handle handle, int func, int arg, u
>         for (i = 0; i < 4; i++)
>                 args_buff[i] = (arg >> i * 8) & 0xFF;
>
> -       obj = acpi_evaluate_dsm_typed(handle, nouveau_op_dsm_muid, nouveau_op_dsm_rid,
> -                                     func, &argv4, ACPI_TYPE_BUFFER);
> +       obj = acpi_evaluate_dsm(handle, nouveau_op_dsm_muid, nouveau_op_dsm_rid,
> +                               func, &argv4);
>         if (!obj) {
>                 acpi_handle_info(handle, "failed to evaluate _DSM\n");
>                 return AE_ERROR;
> -       } else {
> +       } else if (obj->type == ACPI_TYPE_BUFFER) {
>                 if (!result && obj->buffer.length == 4) {
>                         *result  = obj->buffer.pointer[0];
>                         *result |= (obj->buffer.pointer[1] << 8);
> @@ -101,6 +101,15 @@ static int nouveau_evaluate_optimus_dsm(acpi_handle handle, int func, int arg, u
>                         *result |= (obj->buffer.pointer[3] << 24);
>                 }
>                 ACPI_FREE(obj);
> +       } else if (obj->type == ACPI_TYPE_INTEGER &&
> +                  obj->integer.value == 0x80000002) {
> +               acpi_handle_debug(handle, "failed to query Optimus _DSM\n");
> +               ACPI_FREE(obj);
> +               return -ENODEV;

should this be AE_ERROR?

> +       } else {
> +               acpi_handle_err(handle, "unexpected returned value by Optimus _DSM\n");
> +               ACPI_FREE(obj);
> +               return AE_ERROR;
>         }
>
>         return 0;
> --
> 2.4.1
>
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