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 X-Spam-Level: X-Spam-Status: No, score=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C001C433B4 for ; Thu, 29 Apr 2021 21:25:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDA7361441 for ; Thu, 29 Apr 2021 21:25:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233315AbhD2V0m (ORCPT ); Thu, 29 Apr 2021 17:26:42 -0400 Received: from relay5-d.mail.gandi.net ([217.70.183.197]:55029 "EHLO relay5-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233293AbhD2V0m (ORCPT ); Thu, 29 Apr 2021 17:26:42 -0400 X-Originating-IP: 90.65.108.55 Received: from localhost (lfbn-lyo-1-1676-55.w90-65.abo.wanadoo.fr [90.65.108.55]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay5-d.mail.gandi.net (Postfix) with ESMTPSA id 621A81C0004; Thu, 29 Apr 2021 21:25:53 +0000 (UTC) Date: Thu, 29 Apr 2021 23:25:53 +0200 From: Alexandre Belloni To: Mian Yousaf Kaukab Cc: a.zummo@towertech.it, linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rtc: pcf2127: handle timestamp interrupts Message-ID: References: <20210429144758.4552-1-ykaukab@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210429144758.4552-1-ykaukab@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org Hello, On 29/04/2021 16:47:58+0200, Mian Yousaf Kaukab wrote: > commit 03623b4b041c ("rtc: pcf2127: add tamper detection support") > added support for timestamp interrupts. However they are not being > handled in the irq handler. If a timestamp interrupt occurs it > results in kernel disabling the interrupt and displaying the call > trace: > > [ 121.145580] irq 78: nobody cared (try booting with the "irqpoll" option) > ... > [ 121.238087] [<00000000c4d69393>] irq_default_primary_handler threaded [<000000000a90d25b>] pcf2127_rtc_irq [rtc_pcf2127] > [ 121.248971] Disabling IRQ #78 > > Handle timestamp interrupts in pcf2127_rtc_irq(). Display a message > in kernel log when a timestamp interrupt occurs. Don’t check for > TSF1 and TSF2 flags in timestamp0_show() as they are cleared in the > IRQ handler now. This breaks an important functionality (as I already replied to a previous fix a while ago) as then there is no way to know whether the timestamp is bogus or if an event really happened. Please fix properly. > > Signed-off-by: Mian Yousaf Kaukab > --- > drivers/rtc/rtc-pcf2127.c | 34 +++++++++++++++++++++++++--------- > 1 file changed, 25 insertions(+), 9 deletions(-) > > diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c > index d13c20a2adf7..0dbc0473cc68 100644 > --- a/drivers/rtc/rtc-pcf2127.c > +++ b/drivers/rtc/rtc-pcf2127.c > @@ -94,6 +94,13 @@ > #define PCF2127_WD_VAL_MAX 255 > #define PCF2127_WD_VAL_DEFAULT 60 > > +/* Mask for currently enabled interrupts */ > +#define PCF2127_CTRL1_IRQ_MASK (PCF2127_BIT_CTRL1_TSF1) > +#define PCF2127_CTRL2_IRQ_MASK ( \ > + PCF2127_BIT_CTRL2_AF | \ > + PCF2127_BIT_CTRL2_WDTF | \ > + PCF2127_BIT_CTRL2_TSF2) > + > struct pcf2127 { > struct rtc_device *rtc; > struct watchdog_device wdd; > @@ -437,20 +444,33 @@ static int pcf2127_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) > static irqreturn_t pcf2127_rtc_irq(int irq, void *dev) > { > struct pcf2127 *pcf2127 = dev_get_drvdata(dev); > - unsigned int ctrl2 = 0; > + unsigned int ctrl1, ctrl2; > int ret = 0; > > + ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL1, &ctrl1); > + if (ret) > + return IRQ_NONE; > + > ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2); > if (ret) > return IRQ_NONE; > > - if (!(ctrl2 & PCF2127_BIT_CTRL2_AF)) > + if (!(ctrl1 & PCF2127_CTRL1_IRQ_MASK || ctrl2 & PCF2127_CTRL2_IRQ_MASK)) > return IRQ_NONE; > > - regmap_write(pcf2127->regmap, PCF2127_REG_CTRL2, > - ctrl2 & ~(PCF2127_BIT_CTRL2_AF | PCF2127_BIT_CTRL2_WDTF)); > + if (ctrl1 & PCF2127_CTRL1_IRQ_MASK) > + regmap_write(pcf2127->regmap, PCF2127_REG_CTRL1, > + ctrl1 & ~PCF2127_CTRL1_IRQ_MASK); > > - rtc_update_irq(pcf2127->rtc, 1, RTC_IRQF | RTC_AF); > + if (ctrl2 & PCF2127_CTRL2_IRQ_MASK) > + regmap_write(pcf2127->regmap, PCF2127_REG_CTRL2, > + ctrl2 & ~PCF2127_CTRL2_IRQ_MASK); > + > + if (ctrl1 & PCF2127_BIT_CTRL1_TSF1 || ctrl2 & PCF2127_BIT_CTRL2_TSF2) > + dev_info(dev, "timestamp interrupt generated"); > + Please do not add random strings in the kernel, this will probably never be seen by any real user. > + if (ctrl2 & PCF2127_BIT_CTRL2_AF) > + rtc_update_irq(pcf2127->rtc, 1, RTC_IRQF | RTC_AF); > > pcf2127_wdt_active_ping(&pcf2127->wdd); > > @@ -524,10 +544,6 @@ static ssize_t timestamp0_show(struct device *dev, > if (ret) > return ret; > > - if (!(data[PCF2127_REG_CTRL1] & PCF2127_BIT_CTRL1_TSF1) && > - !(data[PCF2127_REG_CTRL2] & PCF2127_BIT_CTRL2_TSF2)) > - return 0; > - > tm.tm_sec = bcd2bin(data[PCF2127_REG_TS_SC] & 0x7F); > tm.tm_min = bcd2bin(data[PCF2127_REG_TS_MN] & 0x7F); > tm.tm_hour = bcd2bin(data[PCF2127_REG_TS_HR] & 0x3F); > -- > 2.26.2 > -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com