Re: [PATCH] usb: gadget: udc: bdc: Remove unnecessary NULL checks in bdc_req_complete

From: Nathan Chancellor
Date: Thu Feb 20 2020 - 23:58:00 EST


I know it has been a while but ping?

On Tue, Oct 22, 2019 at 05:20:15PM -0700, Nathan Chancellor wrote:
> When building with Clang + -Wtautological-pointer-compare:
>
> drivers/usb/gadget/udc/bdc/bdc_ep.c:543:28: warning: comparison of
> address of 'req->queue' equal to a null pointer is always false
> [-Wtautological-pointer-compare]
> if (req == NULL || &req->queue == NULL || &req->usb_req == NULL)
> ~~~~~^~~~~ ~~~~
> drivers/usb/gadget/udc/bdc/bdc_ep.c:543:51: warning: comparison of
> address of 'req->usb_req' equal to a null pointer is always false
> [-Wtautological-pointer-compare]
> if (req == NULL || &req->queue == NULL || &req->usb_req == NULL)
> ~~~~~^~~~~~~ ~~~~
> 2 warnings generated.
>
> As it notes, these statements will always evaluate to false so remove
> them.
>
> Fixes: efed421a94e6 ("usb: gadget: Add UDC driver for Broadcom USB3.0 device controller IP BDC")
> Link: https://github.com/ClangBuiltLinux/linux/issues/749
> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> ---
>
> Note: I am not sure if these checks were intended to check if the
> contents of these arrays were NULL or if there should be some other
> checks in lieu of these; I am not familiar with the USB subsystem to
> answer this but I will happily respin the patch if this is not correct.
>
> drivers/usb/gadget/udc/bdc/bdc_ep.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/gadget/udc/bdc/bdc_ep.c b/drivers/usb/gadget/udc/bdc/bdc_ep.c
> index a4d9b5e1e50e..d49c6dc1082d 100644
> --- a/drivers/usb/gadget/udc/bdc/bdc_ep.c
> +++ b/drivers/usb/gadget/udc/bdc/bdc_ep.c
> @@ -540,7 +540,7 @@ static void bdc_req_complete(struct bdc_ep *ep, struct bdc_req *req,
> {
> struct bdc *bdc = ep->bdc;
>
> - if (req == NULL || &req->queue == NULL || &req->usb_req == NULL)
> + if (req == NULL)
> return;
>
> dev_dbg(bdc->dev, "%s ep:%s status:%d\n", __func__, ep->name, status);
> --
> 2.23.0
>