Hello Suzuki K Poulose, This is a semi-automatic email about new static checker warnings. The patch 743256e214e8: "coresight: tmc: Clean up device specific data" from May 22, 2019, leads to the following Smatch complaint: drivers/hwtracing/coresight/coresight-tmc-etr.c:625 tmc_etr_free_flat_buf() warn: variable dereferenced before check 'flat_buf' (see line 623) drivers/hwtracing/coresight/coresight-tmc-etr.c 622 struct etr_flat_buf *flat_buf = etr_buf->private; 623 struct device *real_dev = flat_buf->dev->parent; ^^^^^^^^^^ The patch introduces a new NULL check 624 625 if (flat_buf && flat_buf->daddr) ^^^^^^^^ but the existing code assumed it can be NULL. 626 dma_free_coherent(real_dev, flat_buf->size, 627 flat_buf->vaddr, flat_buf->daddr); regards, dan carpenter