From f4ee7fac50d8c8e97a0f68c19c9fe666a211321e Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 7 Sep 2017 16:14:31 +0200 Subject: [PATCH] usb: gadget: dummy: fix nonsensical comparisons commit 7661ca09b2ff98f48693f431bb01fed62830e433 upstream. gcc-8 points out two comparisons that are clearly bogus and almost certainly not what the author intended to write: drivers/usb/gadget/udc/dummy_hcd.c: In function 'set_link_state_by_speed': drivers/usb/gadget/udc/dummy_hcd.c:379:31: error: bitwise comparison always evaluates to false [-Werror=tautological-compare] USB_PORT_STAT_ENABLE) == 1 && ^~ drivers/usb/gadget/udc/dummy_hcd.c:381:25: error: bitwise comparison always evaluates to false [-Werror=tautological-compare] USB_SS_PORT_LS_U0) == 1 && ^~ I looked at the code for a bit and came up with a change that makes it look like what the author probably meant here. This makes it look reasonable to me and to gcc, shutting up the warning. It does of course change behavior as the two conditions are actually evaluated rather than being hardcoded to false, and I have made no attempt at verifying that the changed logic makes sense in the context of a USB HCD, so that part needs to be reviewed carefully. Fixes: 1cd8fd2887e1 ("usb: gadget: dummy_hcd: add SuperSpeed support") Cc: Tatyana Brokhman Cc: Felipe Balbi Acked-by: Alan Stern Signed-off-by: Arnd Bergmann Signed-off-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/udc/dummy_hcd.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c index 2154416..8f34dcb 100644 --- a/drivers/usb/gadget/udc/dummy_hcd.c +++ b/drivers/usb/gadget/udc/dummy_hcd.c @@ -313,11 +313,10 @@ static void set_link_state_by_speed(struct dummy_hcd *dum_hcd) USB_PORT_STAT_CONNECTION) == 0) dum_hcd->port_status |= (USB_PORT_STAT_C_CONNECTION << 16); - if ((dum_hcd->port_status & - USB_PORT_STAT_ENABLE) == 1 && - (dum_hcd->port_status & - USB_SS_PORT_LS_U0) == 1 && - dum_hcd->rh_state != DUMMY_RH_SUSPENDED) + if ((dum_hcd->port_status & USB_PORT_STAT_ENABLE) && + (dum_hcd->port_status & + USB_PORT_STAT_LINK_STATE) == USB_SS_PORT_LS_U0 && + dum_hcd->rh_state != DUMMY_RH_SUSPENDED) dum_hcd->active = 1; } } else { -- 2.7.4