linux-kernel - [PATCH] usb: gadget: udc: bdc: Remove unnecessary NULL checks in bdc_req

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Message-Id: <20191023002014.22571-1-natechancellor@gmail.com>
Date:   Tue, 22 Oct 2019 17:20:15 -0700
From:   Nathan Chancellor <natechancellor@...il.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Felipe Balbi <balbi@...nel.org>,
        Ashwini Pahuja <ashwini.linux@...il.com>,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
        clang-built-linux@...glegroups.com,
        Nathan Chancellor <natechancellor@...il.com>
Subject: [PATCH] usb: gadget: udc: bdc: Remove unnecessary NULL checks in bdc_req_complete

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@...il.com>
---

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