From patchwork Thu Jan 26 14:20:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13117210 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69B06C61DA7 for ; Thu, 26 Jan 2023 14:23:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231847AbjAZOXB (ORCPT ); Thu, 26 Jan 2023 09:23:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230287AbjAZOW7 (ORCPT ); Thu, 26 Jan 2023 09:22:59 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8CE65113E4; Thu, 26 Jan 2023 06:22:58 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2928661844; Thu, 26 Jan 2023 14:22:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D67DC4339C; Thu, 26 Jan 2023 14:22:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674742977; bh=DNEhyu7u4f062FvvbtsFWr1nXt0qu/y1C2h9iu3ZUpA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lyvjj+++zBplLPtJ3Fe6CTaq9zUg02yWKvoLq+i3X1BqE1/faXTCQLfga0vyVbHAi 8DdC1cfRTNkWd4dPYrRaY/l9T157clSt4RXJmvfkRKBojoC4tTEvKtp6B+y7BbC0aT K44y8f8AYiuCf1Y4cEXM/kyLVK1RX4rTYDoQ0MNYoHY3NUFy1raebW375ckHPoea2b qUHhfYUxah8JfAVY55E99k2inM6PC7sFHdx2L1Mjm2ce3KNhyEl28dm+PT5RLZ8Mme osL36OMJlZlVXW8nLAsrSFOGie4Y3YQDKFFc5Paz4XyJ4RR3F5uuUmAKgcIOfpg28g 3uUZcg39+hkaw== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1pL39c-0006iE-01; Thu, 26 Jan 2023 15:23:04 +0100 From: Johan Hovold To: Alexandre Belloni , Bjorn Andersson Cc: Andy Gross , Konrad Dybcio , Alessandro Zummo , Rob Herring , Krzysztof Kozlowski , Maximilian Luz , linux-arm-msm@vger.kernel.org, linux-rtc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , stable@vger.kernel.org Subject: [PATCH 01/24] rtc: pm8xxx: fix set-alarm race Date: Thu, 26 Jan 2023 15:20:34 +0100 Message-Id: <20230126142057.25715-2-johan+linaro@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230126142057.25715-1-johan+linaro@kernel.org> References: <20230126142057.25715-1-johan+linaro@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Make sure to disable the alarm before updating the four alarm time registers to avoid spurious alarms during the update. Note that the disable needs to be done outside of the ctrl_reg_lock section to prevent a racing alarm interrupt from disabling the newly set alarm when the lock is released. Fixes: 9a9a54ad7aa2 ("drivers/rtc: add support for Qualcomm PMIC8xxx RTC") Cc: stable@vger.kernel.org # 3.1 Signed-off-by: Johan Hovold --- drivers/rtc/rtc-pm8xxx.c | 24 ++++++++++-------------- 1 file changed, 10 insertions(+), 14 deletions(-) diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c index 716e5d9ad74d..d114f0da537d 100644 --- a/drivers/rtc/rtc-pm8xxx.c +++ b/drivers/rtc/rtc-pm8xxx.c @@ -221,7 +221,6 @@ static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { int rc, i; u8 value[NUM_8_BIT_RTC_REGS]; - unsigned int ctrl_reg; unsigned long secs, irq_flags; struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; @@ -233,6 +232,11 @@ static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) secs >>= 8; } + rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, + regs->alarm_en, 0); + if (rc) + return rc; + spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags); rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value, @@ -242,19 +246,11 @@ static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) goto rtc_rw_fail; } - rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg); - if (rc) - goto rtc_rw_fail; - - if (alarm->enabled) - ctrl_reg |= regs->alarm_en; - else - ctrl_reg &= ~regs->alarm_en; - - rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg); - if (rc) { - dev_err(dev, "Write to RTC alarm control register failed\n"); - goto rtc_rw_fail; + if (alarm->enabled) { + rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, + regs->alarm_en, regs->alarm_en); + if (rc) + goto rtc_rw_fail; } dev_dbg(dev, "Alarm Set for h:m:s=%ptRt, y-m-d=%ptRdr\n",