Commit 43daa3c4 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Greg Kroah-Hartman

usb: gadget: dummy: fix nonsensical comparisons

commit 7661ca09 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: 1cd8fd28 ("usb: gadget: dummy_hcd: add SuperSpeed support")
Cc: Tatyana Brokhman <tlinder@codeaurora.org>
Cc: Felipe Balbi <balbi@kernel.org>
Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent af70fc34
......@@ -379,11 +379,10 @@ 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 {
......
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