And I correct my commit message because platform_get_resource returns null if fails. Here is it. The return value of platform_get_resource() could be null when there is no suitable resource. So it should be better to check it to avoid the use of null pointer in release_mem_region(). Fixes: 4808a1c02611 ("[PATCH] USB: Add isp116x-hcd USB host controller driver") Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx> --- Changelog: v3 -> v4 *Change 1. Just skip the use of null pointer instead of directly return. *Change 2. Add the driver name in the subject line. *Change 3. Correct commit message. --- drivers/usb/host/isp116x-hcd.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/isp116x-hcd.c b/drivers/usb/host/isp116x-hcd.c index 8835f6bd528e..aacaf6e2ddca 100644 --- a/drivers/usb/host/isp116x-hcd.c +++ b/drivers/usb/host/isp116x-hcd.c @@ -1541,10 +1541,13 @@ static int isp116x_remove(struct platform_device *pdev) iounmap(isp116x->data_reg); res = platform_get_resource(pdev, IORESOURCE_MEM, 1); - release_mem_region(res->start, 2); + if (res) + release_mem_region(res->start, 2); + iounmap(isp116x->addr_reg); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - release_mem_region(res->start, 2); + if (res) + release_mem_region(res->start, 2); usb_put_hcd(hcd); return 0; -- 2.25.1