Hello Lanqing Liu,
The patch f4487db58eb7: "serial: sprd: Add DMA mode support" from Mar
4, 2019, leads to the following static checker warning:
drivers/tty/serial/sprd_serial.c:1141 sprd_remove()
error: we previously assumed 'sup' could be null (see line 1132)
drivers/tty/serial/sprd_serial.c
1128 static int sprd_remove(struct platform_device *dev)
1129 {
1130 struct sprd_uart_port *sup = platform_get_drvdata(dev);
1131
1132 if (sup) {
^^^
Check
1133 uart_remove_one_port(&sprd_uart_driver, &sup->port);
1134 sprd_port[sup->port.line] = NULL;
1135 sprd_ports_num--;
1136 }
1137
1138 if (!sprd_ports_num)
1139 uart_unregister_driver(&sprd_uart_driver);
1140
1141 sprd_rx_free_buf(sup);
^^^
Unchecked dereference inside function
1142
1143 return 0;
1144 }
regards,
dan carpenter
