From mboxrd@z Thu Jan 1 00:00:00 1970 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 730FCC678D5 for ; Tue, 7 Mar 2023 17:50:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232229AbjCGRud (ORCPT ); Tue, 7 Mar 2023 12:50:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232157AbjCGRuJ (ORCPT ); Tue, 7 Mar 2023 12:50:09 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2FA53231ED for ; Tue, 7 Mar 2023 09:44:52 -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 ams.source.kernel.org (Postfix) with ESMTPS id D857AB81851 for ; Tue, 7 Mar 2023 17:44:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F05B0C4339B; Tue, 7 Mar 2023 17:44:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678211089; bh=eiyPRHTKbFMhk/WfNo54jTafuAH6RpDmIKMet5d2GsI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hmoGCQmx8SwIzaPT646FlkCw6zbe+KKfqqfUw/FHLWSX/S+CYOSOB+Rwn0up/eZ5S EKp1UDT6emh1KrTdYWz+D3TpG/bD2ueYQjuwgkUjN3zLEarQHihPv/KCUsMrSs3Q3q jHB1Mwq2DglxYV5SmAPZrpiS/8RFDNqJfv8Ik2NM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Johan Hovold , David Collins , Alexandre Belloni Subject: [PATCH 6.2 0749/1001] rtc: pm8xxx: fix set-alarm race Date: Tue, 7 Mar 2023 17:58:41 +0100 Message-Id: <20230307170054.225071429@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Johan Hovold commit c88db0eff9722fc2b6c4d172a50471d20e08ecc6 upstream. 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 Reviewed-by: David Collins Link: https://lore.kernel.org/r/20230202155448.6715-2-johan+linaro@kernel.org Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-pm8xxx.c | 24 ++++++++++-------------- 1 file changed, 10 insertions(+), 14 deletions(-) --- a/drivers/rtc/rtc-pm8xxx.c +++ b/drivers/rtc/rtc-pm8xxx.c @@ -221,7 +221,6 @@ static int pm8xxx_rtc_set_alarm(struct d { 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 d 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 d 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",