Re: [PATCH v2 08/10] drm/panfrost: Add the MT8192 GPU ID

[Chen-Yu Tsai <wenst@chromium.org>]

On Tue, Feb 21, 2023 at 11:37 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com> wrote:
>
> From: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
>
> MediaTek MT8192 has a Mali-G57 with a special GPU ID. Add its GPU ID,
> but treat it as otherwise identical to a standard Mali-G57.
>
> We do _not_ fix up the GPU ID here -- userspace needs to be aware of the
> special GPU ID, in case we find functional differences between
> MediaTek's implementation and the standard Mali-G57 down the line.

> Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> Reviewed-by: Steven Price <steven.price@arm.com>

Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>

FYI MT8195 has a minor revision for Mali-G57. See https://crrev.com/c/2834981
The commit doesn't say what issues were resolved or still linger though.

> ---
>  drivers/gpu/drm/panfrost/panfrost_gpu.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.c b/drivers/gpu/drm/panfrost/panfrost_gpu.c
> index 6452e4e900dd..d28b99732dde 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gpu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gpu.c
> @@ -204,6 +204,14 @@ static const struct panfrost_model gpu_models[] = {
>
>         GPU_MODEL(g57, 0x9001,
>                 GPU_REV(g57, 0, 0)),
> +
> +       /* MediaTek MT8192 has a Mali-G57 with a different GPU ID from the
> +        * standard. Arm's driver does not appear to handle this model.
> +        * ChromeOS has a hack downstream for it. Treat it as equivalent to
> +        * standard Mali-G57 for now.
> +        */
> +       GPU_MODEL(g57, 0x9003,
> +               GPU_REV(g57, 0, 0)),
>  };
>
>  static void panfrost_gpu_init_features(struct panfrost_device *pfdev)
> --
> 2.39.2
>