Hello Michael Walle,
This is a semi-automatic email about new static checker warnings.
The patch a092ab25fdaa: "tty: serial: fsl_lpuart: fix DMA mapping"
from Mar 6, 2020, leads to the following Smatch complaint:
drivers/tty/serial/fsl_lpuart.c:1237 lpuart_dma_rx_free()
error: we previously assumed 'chan' could be null (see line 1234)
drivers/tty/serial/fsl_lpuart.c
1228 static void lpuart_dma_rx_free(struct uart_port *port)
1229 {
1230 struct lpuart_port *sport = container_of(port,
1231 struct lpuart_port, port);
1232 struct dma_chan *chan = sport->dma_rx_chan;
1233
1234 if (chan)
^^^^
The patch adds a check
1235 dmaengine_terminate_all(chan);
1236
1237 dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
^^^^^^
and an unchecked dereference.
1238 kfree(sport->rx_ring.buf);
1239 sport->rx_ring.tail = 0;
regards,
dan carpenter
