[PATCH 1/1] drm/amd/display: remove oem i2c adapter on finish

[Deucher, Alexander]

[AMD Official Use Only - AMD Internal Distribution Only]

> -----Original Message-----
> From: McRae, Geoffrey <Geoffrey.McRae at amd.com>
> Sent: Thursday, August 28, 2025 8:52 AM
> To: Wentland, Harry <Harry.Wentland at amd.com>
> Cc: Deucher, Alexander <Alexander.Deucher at amd.com>; amd-
> gfx at lists.freedesktop.org; McRae, Geoffrey <Geoffrey.McRae at amd.com>
> Subject: [PATCH 1/1] drm/amd/display: remove oem i2c adapter on finish
>
> Fixes a bug where unbinding of the GPU would leave the oem i2c adapter
> registered resuling in a null pointer dereference when applications try to access the
> invalid device.
>
> Cc: Harry Wentland <harry.wentland at amd.com>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Signed-off-by: Geoffrey McRae <geoffrey.mcrae at amd.com>

Can you add a Fixes: tag?  With that added,
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

> Change-Id: I9466b489859c3963653976e54818254596b5a13b
> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index b944abea306d..ef7b59fe6f4d 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -2957,6 +2957,16 @@ static int dm_oem_i2c_hw_init(struct amdgpu_device
> *adev)
>       return 0;
>  }
>
> +static void dm_oem_i2c_hw_fini(struct amdgpu_device *adev) {
> +     struct amdgpu_display_manager *dm = &adev->dm;
> +     if (dm->oem_i2c) {
> +             i2c_del_adapter(&dm->oem_i2c->base);
> +             kfree(dm->oem_i2c);
> +             dm->oem_i2c = NULL;
> +     }
> +}
> +
>  /**
>   * dm_hw_init() - Initialize DC device
>   * @ip_block: Pointer to the amdgpu_ip_block for this hw instance.
> @@ -3007,7 +3017,7 @@ static int dm_hw_fini(struct amdgpu_ip_block *ip_block)
> {
>       struct amdgpu_device *adev = ip_block->adev;
>
> -     kfree(adev->dm.oem_i2c);
> +     dm_oem_i2c_hw_fini(adev);
>
>       amdgpu_dm_hpd_fini(adev);
>
> --
> 2.43.0