From mboxrd@z Thu Jan 1 00:00:00 1970 From: horms@verge.net.au (Simon Horman) Date: Mon, 25 May 2015 09:53:46 +0900 Subject: [PATCH] usb: renesas_usbhs: avoid uninitialized variable use In-Reply-To: References: <16028110.26u0uMKA2O@wuerfel> Message-ID: <20150525005346.GA24690@verge.net.au> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, May 22, 2015 at 11:33:57AM +0000, Yoshihiro Shimoda wrote: > Hi Arnd, > > > Sent: Friday, May 22, 2015 8:07 PM > > > > After the renesas_usbhs driver is enabled in ARM multi_v7_defconfig, > > we now get a new warning: > > > > renesas_usbhs/mod.c: In function 'usbhs_interrupt': > > renesas_usbhs/mod.c:246:7: warning: 'intenb1' may be used uninitialized in this function [-Wmaybe-uninitialized] > > > > gcc correctly points to a problem here, for the case that the > > device is in host mode, we use the intenb1 variable without > > having assigned it first. The state->intsts1 has a similar > > problem, but gcc cannot know that. > > > > This avoids the problem by initializing both sides of the > > comparison to zero when we don't read them from the respective > > registers. > > > > Signed-off-by: Arnd Bergmann > > Fixes: 88a25e02f3 ("usb: renesas_usbhs: Add access control for INTSTS1 and INTENB1 register") > > Thank you very much for the patch! > > Acked-by: Yoshihiro Shimoda > > (I'm not sure why a toolchain I used (Linaro GCC 2014.11) doesn't show this warning...) > > Best regards, > Yoshihiro Shimoda Reviewed-by: Simon Horman > > > diff --git a/drivers/usb/renesas_usbhs/mod.c b/drivers/usb/renesas_usbhs/mod.c > > index e5ce6e6d4f51..d4be5d594896 100644 > > --- a/drivers/usb/renesas_usbhs/mod.c > > +++ b/drivers/usb/renesas_usbhs/mod.c > > @@ -223,6 +223,8 @@ static int usbhs_status_get_each_irq(struct usbhs_priv *priv, > > if (usbhs_mod_is_host(priv)) { > > state->intsts1 = usbhs_read(priv, INTSTS1); > > intenb1 = usbhs_read(priv, INTENB1); > > + } else { > > + state->intsts1 = intenb1 = 0; > > } > > > > /* mask */ > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > > the body of a message to majordomo at vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html >