From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 008.lax.mailroute.net (008.lax.mailroute.net [199.89.1.11]) (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 3F0BB1BD03C; Thu, 21 Nov 2024 20:24:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732220700; cv=none; b=noV9fuIEQdYNd00DmXCuWTy3wY768eaADLYjSeKd0uUr5xWv7vR46sSP+egRjDWv8XFiDcaL4G2y6s1osBZKuT6NkNKuSP3jt4B05Z8uC9wRJbOJu5SZLHYr1KMmSCTjbNmFW9bc4knGh8iong07QbVTpn3l/3ebnzst4YmG8qg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732220700; c=relaxed/simple; bh=Y/j4z8wFAn+eixX1q6K7wi4+AgPBCQ+0prB8uKHvyRM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=sRIDL38OWKFgJvSugixlqlYRA4RnGx8BzV1SAMSVZCKOTqDVWXX/KxmEW3gqjLh1aRlMjqWhrnKymc9zPzrl7FVPoCBgr0BYdlA/2CoXYBbfg9Dh3Soz8snzs1b7drqZju5u/vP1L+LIf+mXQwXmoMOcimMMiRfNfCvsJgMN0DA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=Uw1TnlV3; arc=none smtp.client-ip=199.89.1.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="Uw1TnlV3" Received: from localhost (localhost [127.0.0.1]) by 008.lax.mailroute.net (Postfix) with ESMTP id 4XvV8V4Btyz6CmQtD; Thu, 21 Nov 2024 20:24:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:content-type:content-type:in-reply-to :from:from:content-language:references:subject:subject :user-agent:mime-version:date:date:message-id:received:received; s=mr01; t=1732220694; x=1734812695; bh=iqm2iy0lMDtYAHO0SUq9Ov4k KPKe1IsZCAFT77xxoqA=; b=Uw1TnlV3oUtwd/zAkzXt0m3Z3f5tqJ2xxyEmg1vw YyIhwpr+VJa5k2fLrGE2zijJ1n1Xk9qj/NaKy18wTIU+MU/SaRaTy4g6lIxsBmfc wdAJELCoLgcuXDRY7AZOddeQwze+bpd/qelzUSOM2Qm7tt/YSRUPoUZuR2m5clzd UxN8DtdDgr+tLmT8lecHL/8GbfWHowZHkZZ4UMlbj6ErGt0+sTA/Ak4HP3Qm2RYz V0pk/OrRrujs6YxRuYPGmfBWQIJ4oDioblDG89Ppi5ihiAT4pa371IdPFNhav1im AEzQH5iNzLPvk9EVE48EanXL/nxP6uK7Rs/g0NAWKFAIeA== X-Virus-Scanned: by MailRoute Received: from 008.lax.mailroute.net ([127.0.0.1]) by localhost (008.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id rhhwMErpkPva; Thu, 21 Nov 2024 20:24:54 +0000 (UTC) Received: from [100.66.154.22] (unknown [104.135.204.82]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 008.lax.mailroute.net (Postfix) with ESMTPSA id 4XvV8P1CCgz6CmR09; Thu, 21 Nov 2024 20:24:52 +0000 (UTC) Message-ID: Date: Thu, 21 Nov 2024 12:24:51 -0800 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] scsi: ufs: core: sysfs: Prevent div by zero To: Gwendal Grignou , alim.akhtar@samsung.com, avri.altman@wdc.com, quic_cang@quicinc.com, daejun7.park@samsung.com Cc: linux-scsi@vger.kernel.org, stable@vger.kernel.org References: <20241120062522.917157-1-gwendal@chromium.org> Content-Language: en-US From: Bart Van Assche In-Reply-To: <20241120062522.917157-1-gwendal@chromium.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11/19/24 10:25 PM, Gwendal Grignou wrote: > Prevent a division by 0 when monitoring is not enabled. > > Fixes: 1d8613a23f3c ("scsi: ufs: core: Introduce HBA performance monitor sysfs nodes") > > Cc: stable@vger.kernel.org > Signed-off-by: Gwendal Grignou > --- > drivers/ufs/core/ufs-sysfs.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c > index c95906443d5f9..3692b39b35e78 100644 > --- a/drivers/ufs/core/ufs-sysfs.c > +++ b/drivers/ufs/core/ufs-sysfs.c > @@ -485,6 +485,9 @@ static ssize_t read_req_latency_avg_show(struct device *dev, > struct ufs_hba *hba = dev_get_drvdata(dev); > struct ufs_hba_monitor *m = &hba->monitor; > > + if (!m->nr_req[READ]) > + return sysfs_emit(buf, "0\n"); > + > return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[READ]), > m->nr_req[READ])); > } > @@ -552,6 +555,9 @@ static ssize_t write_req_latency_avg_show(struct device *dev, > struct ufs_hba *hba = dev_get_drvdata(dev); > struct ufs_hba_monitor *m = &hba->monitor; > > + if (!m->nr_req[WRITE]) > + return sysfs_emit(buf, "0\n"); > + > return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[WRITE]), > m->nr_req[WRITE])); > } Is anyone using the UFS monitor infrastructure or can it perhaps be removed? Thanks, Bart.