From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030921AbeBNUqo (ORCPT ); Wed, 14 Feb 2018 15:46:44 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:35374 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1030206AbeBNUql (ORCPT ); Wed, 14 Feb 2018 15:46:41 -0500 Date: Wed, 14 Feb 2018 22:46:39 +0200 From: "Michael S. Tsirkin" To: =?iso-8859-1?Q?Marc-Andr=E9?= Lureau Cc: linux-kernel@vger.kernel.org, bhe@redhat.com, slp@redhat.com, somlo@cmu.edu, xiaolong.ye@intel.com Subject: Re: [PATCH v14 3/9] fw_cfg: fix sparse warnings in fw_cfg_sel_endianness() Message-ID: <20180214224149-mutt-send-email-mst@kernel.org> References: <20180214141850.4017-1-marcandre.lureau@redhat.com> <20180214141850.4017-4-marcandre.lureau@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180214141850.4017-4-marcandre.lureau@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 14, 2018 at 03:18:44PM +0100, Marc-André Lureau wrote: > The function is used for both LE & BE target type, use __force casting. > > Fixes: > $ make C=1 CF=-D__CHECK_ENDIAN__ drivers/firmware/qemu_fw_cfg.o > > drivers/firmware/qemu_fw_cfg.c:55:33: warning: restricted __be16 degrades to integer > drivers/firmware/qemu_fw_cfg.c:55:52: warning: restricted __le16 degrades to integer > > Signed-off-by: Marc-André Lureau > --- > drivers/firmware/qemu_fw_cfg.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c > index 90f467232777..85e693287d87 100644 > --- a/drivers/firmware/qemu_fw_cfg.c > +++ b/drivers/firmware/qemu_fw_cfg.c > @@ -52,7 +52,9 @@ static DEFINE_MUTEX(fw_cfg_dev_lock); > /* pick appropriate endianness for selector key */ > static inline u16 fw_cfg_sel_endianness(u16 key) > { > - return fw_cfg_is_mmio ? cpu_to_be16(key) : cpu_to_le16(key); > + return fw_cfg_is_mmio ? > + (u16 __force)cpu_to_be16(key) : > + (u16 __force)cpu_to_le16(key); > } > > /* read chunk of given fw_cfg blob (caller responsible for sanity-check) */ Well the caller does cpu_to_le16 on the result ... All this makes my head spin. IMHO what you want is a wrapper that does iowrite and iowritebe rather than __force. > -- > 2.16.1.73.g5832b7e9f2