]> git.ipfire.org Git - people/arne_f/kernel.git/commit
usb: gadget: dummy: fix nonsensical comparisons
authorArnd Bergmann <arnd@arndb.de>
Thu, 7 Sep 2017 14:14:31 +0000 (16:14 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 13 Dec 2018 08:22:30 +0000 (09:22 +0100)
commitf4ee7fac50d8c8e97a0f68c19c9fe666a211321e
treef1b6fe7d7a8baed61d51eb11faa26d4bc2032953
parent599379965a37d87155f6c98196cd0e6ca1537c70
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 <tlinder@codeaurora.org>
Cc: Felipe Balbi <balbi@kernel.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/gadget/udc/dummy_hcd.c