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=-14.0 required=3.0 tests=BAYES_00,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 6AEB6C64E7C for ; Wed, 2 Dec 2020 12:39:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F7D82222A for ; Wed, 2 Dec 2020 12:39:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727030AbgLBMjW (ORCPT ); Wed, 2 Dec 2020 07:39:22 -0500 Received: from mail-ed1-f68.google.com ([209.85.208.68]:44570 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725999AbgLBMjW (ORCPT ); Wed, 2 Dec 2020 07:39:22 -0500 Received: by mail-ed1-f68.google.com with SMTP id l5so3636326edq.11; Wed, 02 Dec 2020 04:39:00 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=fkWhrCveGzrEexEtL2n4XQHQOORXAlu2mP1oRk1HA1s=; b=FfnH8mrvBXuzkCgtxvgBOE7g8t02pz8AlMcVK6OauFOT5Isc19jDMDUyIimCyZxeDi NkdhFnCVuLknkhnyvcW9euWKm6gelsDE2vc+TEMdzgJn9pnC9UyuXp08GoHfjcP9iW4V xG3yOrFMSJbC1Kzo5mlmhz6J9n08p3GlY2a5KxX8+iENW7wljyDbld/zQQ8Q9TxCeKrJ 18KrhXz6SC/4XAYzy29bOSccahfObNJGo/O4+x1FH3mbkvCDenv6cMuccvXcw8Ax5WNu DRFjS9x15qQC3KK57rh5adbdZn7MCXfPw2jHZO7dE21zctFhVKicO04R6kKVaeVOcv3F jhoA== X-Gm-Message-State: AOAM532TgrpW8DJT08TaCCyiCjWAWExzqM8+Ks7lutD9ZqyKAPjXCT6H MAhnAd6Va6SQ1YKVGzEJeVv9D7lodkM= X-Google-Smtp-Source: ABdhPJyP28J7WuevEQ7UuS3F0FKaSTUOx5QyLIzTJYPzNxsrsL4f8t9cuit+Kn5MjXz63DieBItZSg== X-Received: by 2002:a05:6402:17b5:: with SMTP id j21mr2363942edy.94.1606912714816; Wed, 02 Dec 2020 04:38:34 -0800 (PST) Received: from kozik-lap (adsl-84-226-167-205.adslplus.ch. [84.226.167.205]) by smtp.googlemail.com with ESMTPSA id m24sm1099440ejo.52.2020.12.02.04.38.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Dec 2020 04:38:33 -0800 (PST) Date: Wed, 2 Dec 2020 14:38:31 +0200 From: Krzysztof Kozlowski To: Marek Szyprowski Cc: linux-rtc@vger.kernel.org, linux-samsung-soc@vger.kernel.org, Alexandre Belloni , Alessandro Zummo , Bartlomiej Zolnierkiewicz Subject: Re: [PATCH 1/2] rtc: s3c: Disable all enable (RTC, tick) bits in the probe Message-ID: <20201202123831.GA36340@kozik-lap> References: <20201202111318.5353-1-m.szyprowski@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20201202111318.5353-1-m.szyprowski@samsung.com> Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org On Wed, Dec 02, 2020 at 12:13:17PM +0100, Marek Szyprowski wrote: > Bootloader might use RTC hardware and leave it in the enabled state. Ensure > that the potentially enabled periodic tick interrupts are disabled before > enabling the driver, because they might cause lockup if tick interrupt > happens after disabling RTC gate clock. > > Signed-off-by: Marek Szyprowski > --- > drivers/rtc/rtc-s3c.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c > index 24a41909f049..16a326e95d46 100644 > --- a/drivers/rtc/rtc-s3c.c > +++ b/drivers/rtc/rtc-s3c.c > @@ -503,6 +503,10 @@ static int s3c_rtc_probe(struct platform_device *pdev) > goto err_src_clk; > } > > + /* disable RTC enable bits potentially set by the bootloader */ > + if (info->data->disable) > + info->data->disable(info); > + It took me some time to figure out why this makes sense: disable followed immediately by enable. :) You could add in commit msg that enable() callback does not enable the tick interrupt. Reviewed-by: Krzysztof Kozlowski Best regards, Krzysztof