From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DEAC62C83 for ; Sat, 16 Oct 2021 16:15:40 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id C29C660F70; Sat, 16 Oct 2021 16:15:36 +0000 (UTC) Date: Sat, 16 Oct 2021 21:45:31 +0530 From: Manivannan Sadhasivam To: Greg KH Cc: Joe Perches , hemantk@codeaurora.org, bbhatt@codeaurora.org, loic.poulain@linaro.org, wangqing@vivo.com, mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Manivannan Sadhasivam Subject: Re: [PATCH 3/3] bus: mhi: replace snprintf in show functions with sysfs_emit Message-ID: <20211016161531.GA4048@thinkpad> References: <20211016065734.28802-1-manivannan.sadhasivam@linaro.org> <20211016065734.28802-4-manivannan.sadhasivam@linaro.org> <6ddc01b24b1c72f7e92174a037043b5cfffa3431.camel@perches.com> Precedence: bulk X-Mailing-List: mhi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Sat, Oct 16, 2021 at 05:07:06PM +0200, Greg KH wrote: > On Sat, Oct 16, 2021 at 03:24:17AM -0700, Joe Perches wrote: > > On Sat, 2021-10-16 at 09:37 +0200, Greg KH wrote: > > > On Sat, Oct 16, 2021 at 12:27:34PM +0530, Manivannan Sadhasivam wrote: > > > > From: Qing Wang > > > > coccicheck complains about the use of snprintf() in sysfs show functions. > > [] > > > > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c > > [] > > > > @@ -94,7 +94,7 @@ static ssize_t serial_number_show(struct device *dev, > > > > struct mhi_device *mhi_dev = to_mhi_device(dev); > > > > struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; > > > > > > > > - return snprintf(buf, PAGE_SIZE, "Serial Number: %u\n", > > > > + return sysfs_emit(buf, "Serial Number: %u\n", > > > > mhi_cntrl->serial_number); > > > > > > The text "Serial Number: " should not be in here, right? It's obvious > > > this is a serial number, that's what the documentation and file name > > > says. Userspace should not have to parse sysfs files. > > > > sysfs is ABI right? Parsing or not, it's what's already there. > > If no tools rely on this, and we can change it, we should at least try. > > We can not change ABI if something breaks. If nothing relies on it, > then it is fine to do so. > Hemant, Bhaumik, do you guys know if there are any possible users (scripts/apps) of this ABI? I'm not 100% inclined to change it but if we are _sure_ that there are no users yet, then I'm ok with it. Thanks, Mani > thanks, > > greg k-h