Hello Stanislaw Gruszka, The patch 2735a6dd7df3: "mt76: unify wait_for_mac" from Aug 29, 2018, leads to the following static checker warning: drivers/net/wireless/mediatek/mt76/mt76x02_mac.h:60 mt76x02_wait_for_mac() warn: signedness bug returning '(-5)' drivers/net/wireless/mediatek/mt76/mt76x02_mac.h 53 static inline bool mt76x02_wait_for_mac(struct mt76_dev *dev) 54 { 55 const u32 MAC_CSR0 = 0x1000; 56 int i; 57 58 for (i = 0; i < 500; i++) { 59 if (test_bit(MT76_REMOVED, &dev->state)) 60 return -EIO; ^^^^ This is supposed to be true or false. 61 62 switch (dev->bus->rr(dev, MAC_CSR0)) { 63 case 0: 64 case ~0: 65 break; 66 default: 67 return true; 68 } 69 usleep_range(5000, 10000); 70 } 71 return false; 72 } regards, dan carpenter