| Message ID | 20200423162923.10886-1-natechancellor@gmail.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 7a0fbcf7c308920bc6116b3a5fb21c8cc5fec128 |
| Headers | show |
| Series | USB: gadget: udc: s3c2410_udc: Remove pointless NULL check in s3c2410_udc_nuke | expand |
On Thu, Apr 23, 2020 at 9:30 AM Nathan Chancellor <natechancellor@gmail.com> wrote: > > Clang warns: > > drivers/usb/gadget/udc/s3c2410_udc.c:255:11: warning: comparison of > address of 'ep->queue' equal to a null pointer is always false > [-Wtautological-pointer-compare] > if (&ep->queue == NULL) > ~~~~^~~~~ ~~~~ > 1 warning generated. > > It is not wrong, queue is not a pointer so if ep is not NULL, the > address of queue cannot be NULL. No other driver does a check like this > and this check has been around since the driver was first introduced, > presumably with no issues so it does not seem like this check should be > something else. Just remove it. > > Commit afe956c577b2d ("kbuild: Enable -Wtautological-compare") exposed > this but it is not the root cause of the warning. > > Fixes: 3fc154b6b8134 ("USB Gadget driver for Samsung s3c2410 ARM SoC") > Link: https://github.com/ClangBuiltLinux/linux/issues/1004 > Reported-by: kbuild test robot <lkp@intel.com> > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Thanks for the patch! If anything, I'd be happy to see some more NULL checks against `ep`, though the callers of s3c2410_udc_nuke() also seem quite confident that the pointer is not NULL. Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > --- > drivers/usb/gadget/udc/s3c2410_udc.c | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/drivers/usb/gadget/udc/s3c2410_udc.c b/drivers/usb/gadget/udc/s3c2410_udc.c > index 0507a2ca0f552..80002d97b59d8 100644 > --- a/drivers/usb/gadget/udc/s3c2410_udc.c > +++ b/drivers/usb/gadget/udc/s3c2410_udc.c > @@ -251,10 +251,6 @@ static void s3c2410_udc_done(struct s3c2410_ep *ep, > static void s3c2410_udc_nuke(struct s3c2410_udc *udc, > struct s3c2410_ep *ep, int status) > { > - /* Sanity check */ > - if (&ep->queue == NULL) > - return; > - > while (!list_empty(&ep->queue)) { > struct s3c2410_request *req; > req = list_entry(ep->queue.next, struct s3c2410_request, > > base-commit: ae83d0b416db002fe95601e7f97f64b59514d936 > -- > 2.26.2 > > -- > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group. > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20200423162923.10886-1-natechancellor%40gmail.com.
diff --git a/drivers/usb/gadget/udc/s3c2410_udc.c b/drivers/usb/gadget/udc/s3c2410_udc.c index 0507a2ca0f552..80002d97b59d8 100644 --- a/drivers/usb/gadget/udc/s3c2410_udc.c +++ b/drivers/usb/gadget/udc/s3c2410_udc.c @@ -251,10 +251,6 @@ static void s3c2410_udc_done(struct s3c2410_ep *ep, static void s3c2410_udc_nuke(struct s3c2410_udc *udc, struct s3c2410_ep *ep, int status) { - /* Sanity check */ - if (&ep->queue == NULL) - return; - while (!list_empty(&ep->queue)) { struct s3c2410_request *req; req = list_entry(ep->queue.next, struct s3c2410_request,
Clang warns: drivers/usb/gadget/udc/s3c2410_udc.c:255:11: warning: comparison of address of 'ep->queue' equal to a null pointer is always false [-Wtautological-pointer-compare] if (&ep->queue == NULL) ~~~~^~~~~ ~~~~ 1 warning generated. It is not wrong, queue is not a pointer so if ep is not NULL, the address of queue cannot be NULL. No other driver does a check like this and this check has been around since the driver was first introduced, presumably with no issues so it does not seem like this check should be something else. Just remove it. Commit afe956c577b2d ("kbuild: Enable -Wtautological-compare") exposed this but it is not the root cause of the warning. Fixes: 3fc154b6b8134 ("USB Gadget driver for Samsung s3c2410 ARM SoC") Link: https://github.com/ClangBuiltLinux/linux/issues/1004 Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> --- drivers/usb/gadget/udc/s3c2410_udc.c | 4 ---- 1 file changed, 4 deletions(-) base-commit: ae83d0b416db002fe95601e7f97f64b59514d936