Will allocating wbcon with drmm_kzalloc before calling 
amdgpu_dm_wb_connector_init be more memory-safe as below?


@@ -5790,7 +5791,8 @@ static int amdgpu_dm_initialize_drm_device(struct 
amdgpu_device *adev)
  		link = dc_get_link_at_index(dm->dc, i);

  		if (link->connector_signal == SIGNAL_TYPE_VIRTUAL) {
-			struct amdgpu_dm_wb_connector *wbcon = kzalloc_obj(*wbcon);
+			struct amdgpu_dm_wb_connector *wbcon =
+				drmm_kzalloc(adev_to_drm(adev), sizeof(*wbcon), GFP_KERNEL);

  			if (!wbcon) {
  				drm_err(adev_to_drm(adev), "KMS: Failed to allocate writeback 
connector\n");
@@ -5799,7 +5801,6 @@ static int amdgpu_dm_initialize_drm_device(struct 
amdgpu_device *adev)

  			if (amdgpu_dm_wb_connector_init(dm, wbcon, i)) {
  				drm_err(adev_to_drm(adev), "KMS: Failed to initialize writeback 
connector\n");
-				kfree(wbcon);
  				continue;
  			}

On 5/4/26 18:24, Dmitry Baryshkov wrote:
> The driver uses drm_writeback_connector_init() instead of its drmm
> counterpart, but it doesn't perform the job queue cleanup (neither
> manually nor by calling drm_writeback_connector_cleanup()). On the
> contrary, the drmm_writeback_connector_init() function ensures the
> proper cleanup of the job queue.
> Use drmm_plain_encoder_alloc() to allocate simple encoder and
> drmm_writeback_connector_init() in order to initialize writeback
> connector instance.
> 
> Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
> Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> ---
>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c    |  2 +-
>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c | 18 +++++++++++++-----
>   2 files changed, 14 insertions(+), 6 deletions(-)
> 
> 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 e96a12ff2d31..2ac64495cdb7 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -10683,7 +10683,7 @@ static void dm_set_writeback(struct amdgpu_display_manager *dm,
>   		return;
>   	}
> 
> -	acrtc = to_amdgpu_crtc(wb_conn->encoder.crtc);
> +	acrtc = to_amdgpu_crtc(crtc_state->base.crtc);
>   	if (!acrtc) {
>   		drm_err(adev_to_drm(adev), "no amdgpu_crtc found\n");
>   		kfree(wb_info);
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
> index 110f0173eee6..fdc3da40452f 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
> @@ -169,7 +169,6 @@ static const struct drm_encoder_helper_funcs amdgpu_dm_wb_encoder_helper_funcs =
> 
>   static const struct drm_connector_funcs amdgpu_dm_wb_connector_funcs = {
>   	.fill_modes = drm_helper_probe_single_connector_modes,
> -	.destroy = drm_connector_cleanup,
>   	.reset = amdgpu_dm_connector_funcs_reset,
>   	.atomic_duplicate_state = amdgpu_dm_connector_atomic_duplicate_state,
>   	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> @@ -188,17 +187,26 @@ int amdgpu_dm_wb_connector_init(struct amdgpu_display_manager *dm,
>   	struct dc *dc = dm->dc;
>   	struct dc_link *link = dc_get_link_at_index(dc, link_index);
>   	int res = 0;
> +	struct drm_encoder *encoder;
> +
> +	encoder = drmm_plain_encoder_alloc(&dm->adev->ddev, NULL,
> +					   DRM_MODE_ENCODER_VIRTUAL, NULL);
> +	if (IS_ERR(encoder))
> +		return PTR_ERR(encoder);
> +
> +	drm_encoder_helper_add(encoder, &amdgpu_dm_wb_encoder_helper_funcs);
> +
> +	encoder->possible_crtcs = amdgpu_dm_get_encoder_crtc_mask(dm->adev);
> 
>   	wbcon->link = link;
> 
>   	drm_connector_helper_add(&wbcon->base.base, &amdgpu_dm_wb_conn_helper_funcs);
> 
> -	res = drm_writeback_connector_init(&dm->adev->ddev, &wbcon->base,
> +	res = drmm_writeback_connector_init(&dm->adev->ddev, &wbcon->base,
>   					    &amdgpu_dm_wb_connector_funcs,
> -					    &amdgpu_dm_wb_encoder_helper_funcs,
> +					    encoder,
>   					    amdgpu_dm_wb_formats,
> -					    ARRAY_SIZE(amdgpu_dm_wb_formats),
> -					    amdgpu_dm_get_encoder_crtc_mask(dm->adev));
> +					    ARRAY_SIZE(amdgpu_dm_wb_formats));
> 
>   	if (res)
>   		return res;
>