Hi Paolo,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Paolo-Valerio/net-macb-move-Rx-buffers-alloc-from-link-up-to-open/20260224-023220
base:   net-next/main
patch link:    https://lore.kernel.org/r/20260223182632.1681809-6-pvalerio%40redhat.com
patch subject: [PATCH net-next v2 5/8] net: macb: add XDP support for gem
config: s390-allmodconfig (https://download.01.org/0day-ci/archive/20260224/202602240713.bQWzr8aD-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260224/202602240713.bQWzr8aD-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot [off-list ref]
| Closes: https://lore.kernel.org/oe-kbuild-all/202602240713.bQWzr8aD-lkp@intel.com/ (local)

All warnings (new ones prefixed by >>):

quoted

drivers/net/ethernet/cadence/macb_main.c:2749:10: warning: variable 'err' is uninitialized when used here [-Wuninitialized]

    2749 |                 return err;
         |                        ^~~
   drivers/net/ethernet/cadence/macb_main.c:2743:9: note: initialize the variable 'err' to silence this warning
    2743 |         int err;
         |                ^
         |                 = 0
   1 warning generated.


vim +/err +2749 drivers/net/ethernet/cadence/macb_main.c

89e5785fc8a6b9 drivers/net/macb.c                       Haavard Skinnemoen 2006-11-09  2726  
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2727  static int gem_create_page_pool(struct macb_queue *queue, int qid)
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2728  {
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2729  	struct page_pool_params pp_params = {
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2730  		.order = 0,
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2731  		.flags = PP_FLAG_DMA_MAP,
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2732  		.pool_size = queue->bp->rx_ring_size,
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2733  		.nid = NUMA_NO_NODE,
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2734  		.dma_dir = rcu_access_pointer(queue->bp->prog)
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2735  				? DMA_BIDIRECTIONAL
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2736  				: DMA_FROM_DEVICE,
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2737  		.dev = &queue->bp->pdev->dev,
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2738  		.netdev = queue->bp->dev,
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2739  		.napi = &queue->napi_rx,
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2740  		.max_len = PAGE_SIZE,
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2741  	};
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2742  	struct page_pool *pool;
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2743  	int err;
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2744  
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2745  	/* This can happen in the case of HRESP error.
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2746  	 * Do nothing as page pool is already existing.
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2747  	 */
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2748  	if (queue->page_pool)
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23 @2749  		return err;
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2750  
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2751  	pool = page_pool_create(&pp_params);
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2752  	if (IS_ERR(pool)) {
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2753  		netdev_err(queue->bp->dev, "cannot create rx page pool\n");
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2754  		err = PTR_ERR(pool);
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2755  		goto clear_pool;
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2756  	}
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2757  
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2758  	queue->page_pool = pool;
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2759  
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2760  	err = xdp_rxq_info_reg(&queue->xdp_rxq, queue->bp->dev, qid,
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2761  			       queue->napi_rx.napi_id);
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2762  	if (err < 0) {
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2763  		netdev_err(queue->bp->dev, "xdp: failed to register rxq info\n");
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2764  		goto destroy_pool;
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2765  	}
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2766  
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2767  	err = xdp_rxq_info_reg_mem_model(&queue->xdp_rxq, MEM_TYPE_PAGE_POOL,
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2768  					 queue->page_pool);
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2769  	if (err) {
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2770  		netdev_err(queue->bp->dev, "xdp: failed to register rxq memory model\n");
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2771  		goto unreg_info;
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2772  	}
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2773  
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2774  	return 0;
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2775  
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2776  unreg_info:
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2777  	xdp_rxq_info_unreg(&queue->xdp_rxq);
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2778  destroy_pool:
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2779  	page_pool_destroy(pool);
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2780  clear_pool:
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2781  	queue->page_pool = NULL;
fa62bb4def147c drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2782  
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2783  	return err;
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2784  }
65104588f8cde9 drivers/net/ethernet/cadence/macb_main.c Paolo Valerio      2026-02-23  2785  

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