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Wed, 16 Sep 2026 15:24:33 +0000 (GMT) Received: from smtpav05.fra02v.mail.ibm.com (smtpav05.fra02v.mail.ibm.com [10.20.54.104]) by smtprelay05.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 68GFOTsN52494718 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 16 Sep 2026 15:24:29 GMT Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 78E4A20043; Wed, 16 Sep 2026 15:24:29 +0000 (GMT) Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9EBDF20040; Wed, 16 Sep 2026 15:24:27 +0000 (GMT) Received: from fedora (unknown [9.5.7.39]) by smtpav05.fra02v.mail.ibm.com (Postfix) with ESMTPS; Wed, 16 Sep 2026 15:24:27 +0000 (GMT) Date: Wed, 16 Sep 2026 21:02:13 +0530 From: Amit Machhiwal To: Thorsten Blum Cc: Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , "Ritesh Harjani (IBM)" , Shrikanth Hegde , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] powerpc/sysfs: Remove redundant wait time clamps Message-ID: <20260916205928.ed6f9a7e-66-amachhiw@linux.ibm.com> Mail-Followup-To: Thorsten Blum , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , "Ritesh Harjani (IBM)" , Shrikanth Hegde , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <20260916151254.120629-2-blum@kernel.org> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260916151254.120629-2-blum@kernel.org> X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-Spam-Info: AW1haW4tMjYwOTE2MDIwNCBTYWx0ZWRfX1MKeEM5oGno+ TD/yKnMp+E9lWMFOuVrOppA4MS4jKaGUM5Q+qTyICZrt/9QaUon7fuzNZP0+IdXD1QhtOMeFlxH 0rru5dfRTkU+rGlMAgF7cdNjd7YvEZM= X-Proofpoint-ORIG-GUID: h_8GQgs1B2ldWI7eBrB5MBw1c6gErRxb X-Proofpoint-GUID: iP8mRjI1rMc7DlK3nD45BzSs0JD4b3kR X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwOTE2MDIwNCBTYWx0ZWRfXxw4IM6GsMJOM LqbLtNdR6IERi5mWtXssBuFWpt6iTLMLQvfCbthVTsI3UqdPHoNY+y51FFA4Zc8JliOxAVRuFZA SaqQmv9CM8lT0ufqj3PyVA9qcpAKWNAlxVNH9YhXCpkGPzTrUGWaFDPN8zH9247B9lhBi5BcMZB xG7aandOjo93i3nUsio5zUCDgoP3rk8zISZ1sD21BaZZ5J47EepUzgMCWzsuRy0khEYmPgXa0kY 1TcyUOR7fVyQmzOwwjqra77Bf4WIgj/McB0XmGkeBjfd4V8aYXaGmV7irM02wT7bYxaAQ8EBpvl VCGHwc5SkVTDMEHXcPDhiq82CiEV6Rj9f05M/isazaE/+Y25iQZY6kwUTpn7RtSKrOyapMSSAtD PUUqfd8LfXtCuoDCdQ95KzQq1NeDJT+YzYdsuEaBb5q2mn3uI+1g45euSZTtA0QjjiwE1uFNvoM 020YeEtBzeKxlesOEVA== X-Authority-Analysis: v=2.4 cv=F+7C5ahN c=1 sm=1 tr=0 ts=6aaab4b2 cx=c_pps a=GFwsV6G8L6GxiO2Y/PsHdQ==:117 a=GFwsV6G8L6GxiO2Y/PsHdQ==:17 a=IkcTkHD0fZMA:10 a=VdqzKS8jKosA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=RzCfie-kr_QcCd8fBx8p:22 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=rBgiJsE2jx_ROkl76MsA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-09-16_02,2026-09-16_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 suspectscore=0 phishscore=0 clxscore=1015 malwarescore=0 lowpriorityscore=0 bulkscore=0 spamscore=0 impostorscore=0 adultscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2609040000 definitions=main-2609160204 On 2026/09/16 05:12 PM, Thorsten Blum wrote: > The wait times are u64 and cannot be negative. Remove the redundant > clamps. > > Signed-off-by: Thorsten Blum > --- > arch/powerpc/kernel/sysfs.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c > index 329c1690b5ed..2100c5e2c821 100644 > --- a/arch/powerpc/kernel/sysfs.c > +++ b/arch/powerpc/kernel/sysfs.c > @@ -338,7 +338,7 @@ static ssize_t show_pw20_wait_time(struct device *dev, > time = pw20_wt; > } > > - return sysfs_emit(buf, "%llu\n", time > 0 ? time : 0); The time variables in both show_pw20_wait_time() and show_altivec_idle_wait_time() are u64, so the expression time > 0 ? time : 0 is indeed a no-op for all possible values — when time == 0 the ternary also yields 0, and negative values are impossible by type. The simplification is correct and removes a subtly misleading pattern that implies a signed type. Nit: the commit message could also mention that when time == 0, the ternary still yields 0, making the conditional identity-preserving for all possible inputs — not just the non-negative ones. Strengthens the rationale a little, but not a blocker. Reviewed-by: Amit Machhiwal Thanks, Amit > + return sysfs_emit(buf, "%llu\n", time); > } > > static void set_pw20_wait_entry_bit(void *val) > @@ -460,7 +460,7 @@ static ssize_t show_altivec_idle_wait_time(struct device *dev, > time = altivec_idle_wt; > } > > - return sysfs_emit(buf, "%llu\n", time > 0 ? time : 0); > + return sysfs_emit(buf, "%llu\n", time); > } > > static void set_altivec_idle_wait_entry_bit(void *val)