On Sat, Mar 20, 2021 at 09:31:51AM +0800, Jay Fang wrote: > From: Zihao Tang <tangzihao1@xxxxxxxxxxxxx> > > Fix the following smatch warnings: > > drivers/usb/host/ohci-hcd.c:1318 ohci_hcd_mod_init() warn: > ignoring unreachable code. > > platform_driver_register(&TMIO_OHCI_DRIVER) is the last > platform_driver_register() call in ohci_hcd_mod_init(), so if it > failed, there's no need to unregister it, but just goto error_tmio. > > So remove the unreachable platform_driver_unregister(&TMIO_OHCI_DRIVER). > No functionality change. Doesn't the compiler realize that the call is unreachable, and therefore avoid generating any object for it? It's true that the function call is, strictly speaking, unnecessary. However, it provides a pleasing symmetry and it acts as a guide in the unlikely event that anyone wants to add another platform-specific driver in the future. Also, consider what would happen if somebody ever removes the TMIO_OHCI platform driver entirely. They certainly would remove the corresponding #ifdef...#endif block. But by your way of thinking, they should remove as well the following platform_driver_unregister(&SM501_OHCI_DRIVER) call -- something that is not immediately obvious and is likely to be overlooked. On the whole, I prefer to keep the code as it is. However, if you would like to submit a different patch, adding a comment which explains that the call is known to be unreachable but is retained nonetheless because the maintainer is a crotchety old formalist, I would be willing to apply that. Alan Stern PS: A #ifdef...#endif block containing nothing but a statement label looks a little weird, don't you agree? > Reported-by: kernel test robot <lkp@xxxxxxxxx> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > Signed-off-by: Zihao Tang <tangzihao1@xxxxxxxxxxxxx> > Signed-off-by: Jay Fang <f.fangjian@xxxxxxxxxx> > --- > drivers/usb/host/ohci-hcd.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c > index 1f5e693..2d09ef2 100644 > --- a/drivers/usb/host/ohci-hcd.c > +++ b/drivers/usb/host/ohci-hcd.c > @@ -1319,7 +1319,6 @@ static int __init ohci_hcd_mod_init(void) > > /* Error path */ > #ifdef TMIO_OHCI_DRIVER > - platform_driver_unregister(&TMIO_OHCI_DRIVER); > error_tmio: > #endif > #ifdef SM501_OHCI_DRIVER > -- > 2.7.4 >
