Hi Lorenzo, I love your patch! Yet something to improve: [auto build test ERROR on kvalo-wireless-drivers-next/master] [also build test ERROR on kvalo-wireless-drivers/master v5.15-rc5 next-20211015] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Lorenzo-Bianconi/mt76-mt7921-get... base: https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-ne... master config: x86_64-randconfig-a004-20211015 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project a49f5386ce6b091da66ea7c3a1d9a588d53becf7) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/91d7fb264668cb286a961b82b9052e2e2... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Lorenzo-Bianconi/mt76-mt7921-get-rid-of-unused-variable-in-mt7921_tx_complete_skb/20211016-060448 git checkout 91d7fb264668cb286a961b82b9052e2e23a78f99 # save the attached .config to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/net/wireless/mediatek/mt76/mt7921/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): wcid = rcu_dereference(dev->mt76.wcid[cb->wcid]); ^ >> drivers/net/wireless/mediatek/mt76/mt7921/mac.c:1115:8: error: assigning to 'struct mt76_wcid *' from incompatible type 'void' wcid = rcu_dereference(dev->mt76.wcid[cb->wcid]); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 4 errors generated. vim +/dev +1115 drivers/net/wireless/mediatek/mt76/mt7921/mac.c 163f4d22c118d4 Sean Wang 2021-01-28 1091 163f4d22c118d4 Sean Wang 2021-01-28 1092 void mt7921_tx_complete_skb(struct mt76_dev *mdev, struct mt76_queue_entry *e) 163f4d22c118d4 Sean Wang 2021-01-28 1093 { 163f4d22c118d4 Sean Wang 2021-01-28 1094 if (!e->txwi) { 163f4d22c118d4 Sean Wang 2021-01-28 1095 dev_kfree_skb_any(e->skb); 163f4d22c118d4 Sean Wang 2021-01-28 1096 return; 163f4d22c118d4 Sean Wang 2021-01-28 1097 } 163f4d22c118d4 Sean Wang 2021-01-28 1098 163f4d22c118d4 Sean Wang 2021-01-28 1099 /* error path */ 163f4d22c118d4 Sean Wang 2021-01-28 1100 if (e->skb == DMA_DUMMY_DATA) { 163f4d22c118d4 Sean Wang 2021-01-28 1101 struct mt76_txwi_cache *t; 163f4d22c118d4 Sean Wang 2021-01-28 1102 struct mt7921_txp_common *txp; 163f4d22c118d4 Sean Wang 2021-01-28 1103 u16 token; 163f4d22c118d4 Sean Wang 2021-01-28 1104 163f4d22c118d4 Sean Wang 2021-01-28 1105 txp = mt7921_txwi_to_txp(mdev, e->txwi); 163f4d22c118d4 Sean Wang 2021-01-28 1106 token = le16_to_cpu(txp->hw.msdu_id[0]) & ~MT_MSDU_ID_VALID; d089692bc7938a Lorenzo Bianconi 2021-04-20 1107 t = mt76_token_put(mdev, token); 163f4d22c118d4 Sean Wang 2021-01-28 1108 e->skb = t ? t->skb : NULL; 163f4d22c118d4 Sean Wang 2021-01-28 1109 } 163f4d22c118d4 Sean Wang 2021-01-28 1110 163f4d22c118d4 Sean Wang 2021-01-28 1111 if (e->skb) { 163f4d22c118d4 Sean Wang 2021-01-28 1112 struct mt76_tx_cb *cb = mt76_tx_skb_cb(e->skb); 163f4d22c118d4 Sean Wang 2021-01-28 1113 struct mt76_wcid *wcid; 163f4d22c118d4 Sean Wang 2021-01-28 1114 163f4d22c118d4 Sean Wang 2021-01-28 @1115 wcid = rcu_dereference(dev->mt76.wcid[cb->wcid]); 163f4d22c118d4 Sean Wang 2021-01-28 1116 163f4d22c118d4 Sean Wang 2021-01-28 1117 mt7921_tx_complete_status(mdev, e->skb, wcid_to_sta(wcid), 0, 163f4d22c118d4 Sean Wang 2021-01-28 1118 NULL); 163f4d22c118d4 Sean Wang 2021-01-28 1119 } 163f4d22c118d4 Sean Wang 2021-01-28 1120 } 163f4d22c118d4 Sean Wang 2021-01-28 1121 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org