The static checker reports following warning: drivers/dma/fsl-edma.c:732 fsl_edma_xlate() error: we previously assumed 'chan' could be null (see line 737) The changes of the loop cursor in the iteration may result in NULL dereference when dma_get_slave_channel failed but loop will continue. So use list_for_each_entry_safe() instead of list_for_each_entry() to against this. Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Signed-off-by: Jingchang Lu <b35083@xxxxxxxxxxxxx> --- drivers/dma/fsl-edma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c index 9025300..381e793 100644 --- a/drivers/dma/fsl-edma.c +++ b/drivers/dma/fsl-edma.c @@ -723,13 +723,13 @@ static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma) { struct fsl_edma_engine *fsl_edma = ofdma->of_dma_data; - struct dma_chan *chan; + struct dma_chan *chan, *_chan; if (dma_spec->args_count != 2) return NULL; mutex_lock(&fsl_edma->fsl_edma_mutex); - list_for_each_entry(chan, &fsl_edma->dma_dev.channels, device_node) { + list_for_each_entry_safe(chan, _chan, &fsl_edma->dma_dev.channels, device_node) { if (chan->client_count) continue; if ((chan->chan_id / DMAMUX_NR) == dma_spec->args[0]) { -- 1.8.0 -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html