[PATCH] drm/amd/pm: avoid potential UBSAN issue on legacy asics

[Quan, Evan]

[AMD Official Use Only - General]

Acked-by: Evan Quan <evan.quan at amd.com>

> -----Original Message-----
> From: Chen, Guchun <Guchun.Chen at amd.com>
> Sent: Tuesday, May 9, 2023 9:43 AM
> To: amd-gfx at lists.freedesktop.org; Deucher, Alexander
> <Alexander.Deucher at amd.com>; Zhang, Hawking
> <Hawking.Zhang at amd.com>; Lazar, Lijo <Lijo.Lazar at amd.com>; Quan, Evan
> <Evan.Quan at amd.com>
> Cc: Chen, Guchun <Guchun.Chen at amd.com>
> Subject: [PATCH] drm/amd/pm: avoid potential UBSAN issue on legacy asics
> 
> Prevent further casting on chip MULLINS/KABINI/KAVERI when calling
> amdgpu_dpm_is_overdrive_supported, this can avoid UBSAN complain
> in init sequence.
> 
> Suggested-by: Evan Quan <evan.quan at amd.com>
> Signed-off-by: Guchun Chen <guchun.chen at amd.com>
> ---
>  drivers/gpu/drm/amd/pm/amdgpu_dpm.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> index 86246f69dbe1..ccd3ea89eacf 100644
> --- a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> +++ b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> @@ -1467,8 +1467,14 @@ int amdgpu_dpm_is_overdrive_supported(struct
> amdgpu_device *adev)
>  	} else {
>  		struct pp_hwmgr *hwmgr;
> 
> -		/* SI asic does not carry od_enabled */
> -		if (adev->family == AMDGPU_FAMILY_SI)
> +		/*
> +		 * SI asic and chip MULLINS/KABINI/KAVERI do not carry
> +		 * od_enabled, as its pp_handle is casted from adev.
> +		 */
> +		if ((adev->family == AMDGPU_FAMILY_SI) ||
> +		    (adev->asic_type == CHIP_MULLINS) ||
> +		    (adev->asic_type == CHIP_KABINI) ||
> +		    (adev->asic_type == CHIP_KAVERI))
>  			return false;
> 
>  		hwmgr = (struct pp_hwmgr *)adev->powerplay.pp_handle;
> --
> 2.25.1