media: mtk-jpeg: only init/cancel work for multi-core variants

Single-core variants of this hardware do not use the work at all, and
the worker function is set to NULL, which leads to warnings when
cancelling the work in release callback.

Skip the work init/cancel code when the JPEG hardware isn't multi-core.

Cc: stable@vger.kernel.org
Fixes: 34c519feef3e ("media: mtk-jpeg: fix use-after-free in release path due to uncancelled work")
Fixes: d40e952 ("media: mtk-jpeg: reconstructs the initialization mode of worker")
Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
Link: https://lore.kernel.org/all/20260601073218.1281840-1-zhengxingda@iscas.ac.cn/
Signed-off-by: WangYuli <wangyl5933@chinaunicom.cn>

Author: Icenowy

drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c

@@ -1167,7 +1167,8 @@ static int mtk_jpeg_open(struct file *file)
 		goto free;
 	}
 
-	INIT_WORK(&ctx->jpeg_work, jpeg->variant->jpeg_worker);
+	if (jpeg->variant->multi_core)
+		INIT_WORK(&ctx->jpeg_work, jpeg->variant->jpeg_worker);
 	INIT_LIST_HEAD(&ctx->dst_done_queue);
 	spin_lock_init(&ctx->done_queue_lock);
 	v4l2_fh_init(&ctx->fh, vfd);
@@ -1209,7 +1210,8 @@ static int mtk_jpeg_release(struct file *file)
 	struct mtk_jpeg_dev *jpeg = video_drvdata(file);
 	struct mtk_jpeg_ctx *ctx = mtk_jpeg_file_to_ctx(file);
 
-	cancel_work_sync(&ctx->jpeg_work);
+	if (jpeg->variant->multi_core)
+		cancel_work_sync(&ctx->jpeg_work);
 	mutex_lock(&jpeg->lock);
 	v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
 	v4l2_ctrl_handler_free(&ctx->ctrl_hdl);