From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 5F72456511F; Wed, 9 Sep 2026 14:17:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788963472; cv=none; b=BdK4g+BFhs1+ZYCBTlQfQIvaSurq4gjq6BWWupWQKL5gmxfD1EdosvveHU2SspXiDtIG2VgkK4EChhgOrqZzFbme1JtXMhpr3whPsoRfHEEJ4IGS/WgbvW1zu/r34pnMdKZdq/3MMPFRpVMFEdt5aO3Jd7ttOWvOomAPAH7o4Vk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788963472; c=relaxed/simple; bh=6vn50rvuf1bMU9aPtHl/uKtK8rVIqx1qLqlgT7yW9WY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=k+HMOitOWONJKbFdHOR7PvpkrZEpOGcQ/bWE/1puYlwEFymYHIvyXcFz65WXe1OcVCLxHTEu+AuWw9+hj69gcPAmlTy6y9J11BNZLOF9LUbHig90uhOmqrDsZ0ymODDjN39wpNyI2ZqoPxgQiA2NTmex+dH1PslUIu74gl4JA1A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=icOQIB2b; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="icOQIB2b" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B8A631F00A3A; Wed, 9 Sep 2026 14:17:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788963471; bh=vGHsVCm7ChSbvsCyIREatgiPUOK8+Ma0QuLfy4Fk5PY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=icOQIB2bQxw/RrjruTCpJOi8DMyr52aiughuxsaVvTRefsYslHCArkYU/kqCqPCuh TBvd0DKstqZ1BLIitn5SYgBrzFR6DOquHyV8li+qHwfY5nb5pEWGIppb/LlLJtXJcP 2khcEpldRQN6CcH1XMhYahtNstu7nf5ywZ80hUV4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lad Prabhakar , Wolfram Sang , Alexandre Belloni Subject: [PATCH 6.18 091/583] rtc: rzn1: Handle unset alarm weekday in rzn1_rtc_read_alarm Date: Wed, 9 Sep 2026 15:36:16 +0200 Message-ID: <20260909134241.278549026@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260909134237.773280130@linuxfoundation.org> References: <20260909134237.773280130@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lad Prabhakar commit 457b5dbce31209e65e1184716ed3af59cb1c0372 upstream. RZN1_RTC_ALW is a weekday bitmask where bit N represents weekday N. When no alarm has been configured, the register has its power-on-reset value of zero. rzn1_rtc_read_alarm() uses fls() to convert the weekday bitmask into a weekday number. When RZN1_RTC_ALW is zero, fls(0) returns zero and fls(wday) - 1 evaluates to -1. This invalid weekday is then used to calculate the alarm date and can either leave tm_wday set to -1 or produce a fabricated alarm date. Treat a zero RZN1_RTC_ALW value as an unset alarm weekday and return without calculating the alarm date. Move reading RZN1_RTC_CTL1 before this check so that alrm->enabled is updated for both configured and unconfigured alarms. Fixes: b5ad1bf00d2c4 ("rtc: rzn1: Add alarm support") Cc: stable@vger.kernel.org Signed-off-by: Lad Prabhakar Reviewed-by: Wolfram Sang Tested-by: Wolfram Sang Link: https://patch.msgid.link/20260821211032.13554-5-prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-rzn1.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) --- a/drivers/rtc/rtc-rzn1.c +++ b/drivers/rtc/rtc-rzn1.c @@ -235,13 +235,24 @@ static int rzn1_rtc_read_alarm(struct de if (ret) return ret; + ctl1 = readl(rtc->base + RZN1_RTC_CTL1); + alrm->enabled = !!(ctl1 & (RZN1_RTC_CTL1_ALME | RZN1_RTC_CTL1_1SE)); + min = readl(rtc->base + RZN1_RTC_ALM); hour = readl(rtc->base + RZN1_RTC_ALH); - wday = readl(rtc->base + RZN1_RTC_ALW); tm->tm_sec = 0; tm->tm_min = bcd2bin(min); tm->tm_hour = bcd2bin(hour); + + /* + * If wday is zero, no bit is set in RZN1_RTC_ALW. This is the + * register's power-on reset value. + */ + wday = readl(rtc->base + RZN1_RTC_ALW); + if (!wday) + return 0; + delta_days = ((fls(wday) - 1) - tm->tm_wday + 7) % 7; tm->tm_wday = fls(wday) - 1; @@ -250,9 +261,6 @@ static int rzn1_rtc_read_alarm(struct de rtc_time64_to_tm(alarm, tm); } - ctl1 = readl(rtc->base + RZN1_RTC_CTL1); - alrm->enabled = !!(ctl1 & (RZN1_RTC_CTL1_ALME | RZN1_RTC_CTL1_1SE)); - return 0; }