From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:37021) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gz0Eg-0000ZI-PH for qemu-devel@nongnu.org; Wed, 27 Feb 2019 09:31:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gz0Au-0005zf-39 for qemu-devel@nongnu.org; Wed, 27 Feb 2019 09:27:08 -0500 Received: from mail-ed1-x541.google.com ([2a00:1450:4864:20::541]:34803) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gz0At-0005op-SL for qemu-devel@nongnu.org; Wed, 27 Feb 2019 09:27:08 -0500 Received: by mail-ed1-x541.google.com with SMTP id a16so14075452edn.1 for ; Wed, 27 Feb 2019 06:26:54 -0800 (PST) Date: Wed, 27 Feb 2019 14:26:51 +0000 From: Wei Yang Message-ID: <20190227142651.3enr2eey5bn2v6ls@master> Reply-To: Wei Yang References: <20190226073159.13434-1-richardw.yang@linux.intel.com> <20190226110934-mutt-send-email-mst@kernel.org> <20190227053319.GB5449@richard> <20190227084843-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190227084843-mutt-send-email-mst@kernel.org> Subject: Re: [Qemu-devel] [PATCH] fw_cfg: use __ATTR_RO_MODE to define rev sysfs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Wei Yang , somlo@cmu.edu, qemu-devel@nongnu.org, linux-kernel@vger.kernel.org On Wed, Feb 27, 2019 at 08:51:11AM -0500, Michael S. Tsirkin wrote: >On Wed, Feb 27, 2019 at 01:33:19PM +0800, Wei Yang wrote: >> On Tue, Feb 26, 2019 at 11:10:06AM -0500, Michael S. Tsirkin wrote: >> >On Tue, Feb 26, 2019 at 03:31:59PM +0800, Wei Yang wrote: >> >> Leverage __ATTR_RO_MODE to define rev sysfs instead of using open code >> >> to define the attribute. >> >> >> >> Signed-off-by: Wei Yang >> >> --- >> >> drivers/firmware/qemu_fw_cfg.c | 13 ++++--------- >> >> 1 file changed, 4 insertions(+), 9 deletions(-) >> >> >> >> diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c >> >> index 039e0f91dba8..a1293cbd7adb 100644 >> >> --- a/drivers/firmware/qemu_fw_cfg.c >> >> +++ b/drivers/firmware/qemu_fw_cfg.c >> >> @@ -296,18 +296,13 @@ static int fw_cfg_do_platform_probe(struct platform_device *pdev) >> >> return 0; >> >> } >> >> >> >> -static ssize_t fw_cfg_showrev(struct kobject *k, struct attribute *a, char *buf) >> >> +static ssize_t fw_cfg_rev_show(struct kobject *k, struct kobj_attribute *a, >> >> + char *buf) >> >> { >> >> return sprintf(buf, "%u\n", fw_cfg_rev); >> >> } >> >> - >> >> -static const struct { >> >> - struct attribute attr; >> >> - ssize_t (*show)(struct kobject *k, struct attribute *a, char *buf); >> >> -} fw_cfg_rev_attr = { >> >> - .attr = { .name = "rev", .mode = S_IRUSR }, >> >> - .show = fw_cfg_showrev, >> >> -}; >> >> +static const struct kobj_attribute fw_cfg_rev_attr = >> >> + __ATTR_RO_MODE(fw_cfg_rev, 0400); >> >> >> >> /* fw_cfg_sysfs_entry type */ >> >> struct fw_cfg_sysfs_entry { >> > >> > >> >Looks like this will change the name from "rev" to "fw_cfg_rev". >> >That's a userspace visible change which we should not do lightly. >> >> You are right, I should keep the interface untouched. >> >> To keep it user un-visible, we could change like below: >> >> - __ATTR_RO(fw_cfg_rev); >> + __ATTR_RO(rev); >> >> Is this better for you? > > >Also why use 0400 and not S_IRUSR? > This is interesting. The scripts/checkpatch.pl suggest to use 0400. I am not sure why the script give this suggestion. Maybe we need to fix the script? >> >> -- >> >> 2.19.1 >> >> -- >> Wei Yang >> Help you, Help me -- Wei Yang Help you, Help me