From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH] tty/serial: digicolor: Fix bad usage of IS_ERR_VALUE Date: Tue, 09 Feb 2016 16:26:38 +0100 Message-ID: <4571887.rTPndCnv20@wuerfel> References: <1455030539-10798-1-git-send-email-linux@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1455030539-10798-1-git-send-email-linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: Guenter Roeck , Greg Kroah-Hartman , Baruch Siach , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jiri Slaby , kernel-testers-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrzej Hajda List-Id: linux-serial@vger.kernel.org On Tuesday 09 February 2016 07:08:59 Guenter Roeck wrote: > IS_ERR_VALUE() assumes that its parameter is an unsigned long. > It can not be used to check if an unsigned int reflects an error. > Doing so can result in the following build warning. >=20 > drivers/tty/serial/digicolor-usart.c: In function =E2=80=98digicolor_= uart_probe=E2=80=99: > include/linux/err.h:21:38: warning: > comparison is always false due to limited range of data type > drivers/tty/serial/digicolor-usart.c:485:6: note: > in expansion of macro =E2=80=98IS_ERR_VALUE=E2=80=99 >=20 > If that warning is seen, an error return from platform_get_irq() is m= issed. >=20 >=20 The patch looks correct to me, but what compiler version and which kern= el tree is it that triggered the warning? Andrzej Hajda just modified the definition of IS_ERR_VALUE(), and the changes are still under discussion, but I don't see that warning with any of the versions. Arnd