Re: [PATCH v3 08/11] drm/panfrost: Add the MT8192 GPU ID

From: Chen-Yu Tsai
Date: Fri Feb 24 2023 - 05:08:09 EST


On Thu, Feb 23, 2023 at 9:35 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@xxxxxxxxxxxxx> wrote:
>
> From: Alyssa Rosenzweig <alyssa.rosenzweig@xxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxx>
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> Reviewed-by: Steven Price <steven.price@xxxxxxx>

Reviewed-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>

As previously mentioned, MT8195 Mali G57 has minor revision number 1.
Do we need to handle that?

> ---
> 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
>