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 BCAE7C433EF for ; Tue, 24 May 2022 15:46:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239055AbiEXPq6 (ORCPT ); Tue, 24 May 2022 11:46:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236171AbiEXPq5 (ORCPT ); Tue, 24 May 2022 11:46:57 -0400 X-Greylist: delayed 2197 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 24 May 2022 08:46:55 PDT Received: from mail.hugovil.com (mail.hugovil.com [162.243.120.170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 207E369CD4; Tue, 24 May 2022 08:46:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hugovil.com ; s=x; h=Subject:Content-Transfer-Encoding:Content-Type:Mime-Version: References:In-Reply-To:Message-Id:Cc:To:From:Date:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=T9kVwBVV655q2jjBqBTVTMqSm4y1htgJfQgySVDPZwA=; b=cqpbUo6/iaW2vwimgwGk1A2w6E eUNVFPgjnZyOUhl+jzmlBAg9kYIk7E0H0BEDtSxzbP2dAF+eK78oKcrQANB/NJ5iXxMFqO1usG6Fi HHCFDzdr+eq983CCGF5eE1DlKufzd++Lc7koKQUSm8SAm8naP4MoeBHd5M3WxzmkfW5k=; Received: from modemcable168.174-80-70.mc.videotron.ca ([70.80.174.168]:50202 helo=pettiford) by mail.hugovil.com with esmtpa (Exim 4.92) (envelope-from ) id 1ntWAe-0005Ct-U1; Tue, 24 May 2022 11:10:12 -0400 Date: Tue, 24 May 2022 11:10:04 -0400 From: Hugo Villeneuve To: Alexandre Belloni Cc: Alessandro Zummo , linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org Message-Id: <20220524111004.7b0fd6c492c835e7f1ee22b7@hugovil.com> In-Reply-To: References: <20220309162301.61679-1-alexandre.belloni@bootlin.com> <20220309162301.61679-11-alexandre.belloni@bootlin.com> <20220310110918.41a681474f5a0e11abdedc39@hugovil.com> <20220317112820.7617d0d68f50f24ad0c3739e@hugovil.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 70.80.174.168 X-SA-Exim-Mail-From: hugo@hugovil.com Subject: Re: [PATCH 11/29] rtc: pcf2127: set RTC_FEATURE_ALARM_RES_2S X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.hugovil.com) Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org On Thu, 17 Mar 2022 18:16:17 +0100 Alexandre Belloni wrote: > Hi, > > On 17/03/2022 11:28:20-0400, Hugo Villeneuve wrote: > > On Thu, 10 Mar 2022 21:58:49 +0100 > > Alexandre Belloni wrote: > > > > > On 10/03/2022 11:09:18-0500, Hugo Villeneuve wrote: > > > > On Wed, 9 Mar 2022 17:22:42 +0100 > > > > Alexandre Belloni wrote: > > > > > > > > > The PCF2127 doesn't support UIE because setting an alarm to fire every > > > > > second confuses the chip and the fastest we can go is an alarm every 2 > > > > > seconds. > > > > > > > > Hi Alexandre, > > > > can you describe what "confuses the chip" means? > > > > > > > > In my experimental PCF2131 driver, I activated UIE and it seems to be working fine at 1s intervals, but since it is similar to PCF2127, maybe there is still a problem and I just didn't see it. > > > > > > > > > > Did you remove uie_unsupported? Else, you may have been using uie > > > emulation. In my tests last year, the pcf2127 was failing to reassert > > > the interrupt if an alarm was set every second. The same happens on > > > other NXP based RTCs (i.e. including microcrystal ones). > > > > > > I'm going to test again soon (and also reply to your series). > > > > Hi, > > I have now access to a board with a PCF2129T. > > > > I actually did the test again this afternoon with a pcf2127... > > > I have been able to test with it by sending ioctl RTC_UIE_ON and > > confirm that it exhibits the problem you reported. Basically, the > > first alarm triggers the IRQ after 1s, as expected, but the next > > configured alarm 1s into the future never triggers the IRQ again. But > > the time/date registers seem to be updating (incrementin) correctly > > after that. > > > > ...and so we agree on what we observe. My guess is that the alarm > comparator has a latch that triggers only every second update and so you > need 2 seconds between each alarms. > > [...] > > > I even did some tests where, in pcf2127_rtc_set_alarm(), I disabled > > all the alarm registers (set to 0x80), except for the SECONDS alarm > > register. In this case, I observed that the IRQ is triggered after > > 61s. This seems to indicate that the alarm detection circuitry is > > still somewhat operating (AF flag / INT pin), but there is probably a > > bug in the IC when the configured alarm is close to current time after > > AF is set once... > > > > I also have done other tests by disabling then re-enabling AIE, > > stopping and restarting the oscillator (STOP bit), etc, but to no > > avail. > > > > However, in pcf2127_rtc_set_alarm(), if I set the alarm 2s past the > > current time, instead of 1s, then the IRQ is always triggered after > > 2s. > > > > I have opened a support case with NXP to investigate this strange > > behavior. > > Let me know if you ever get a reply. Hi Alexandre, after two months and a lot of emails with NXP awful technical support, I was never able to have a valid answer to the problem, apart from "Use a new device as the PCF2127 is not recommended for new designs" :( On the other hand, have you had time to look at my patch series for the PCF2131 driver? Thank you, Hugo. > > > > > Signed-off-by: Alexandre Belloni > > > > > --- > > > > > drivers/rtc/rtc-pcf2127.c | 1 + > > > > > 1 file changed, 1 insertion(+) > > > > > > > > > > diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c > > > > > index f8469b134411..63b275b014bd 100644 > > > > > --- a/drivers/rtc/rtc-pcf2127.c > > > > > +++ b/drivers/rtc/rtc-pcf2127.c > > > > > @@ -656,6 +656,7 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap, > > > > > pcf2127->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; > > > > > pcf2127->rtc->range_max = RTC_TIMESTAMP_END_2099; > > > > > pcf2127->rtc->set_start_time = true; /* Sets actual start to 1970 */ > > > > > + set_bit(RTC_FEATURE_ALARM_RES_2S, pcf2127->rtc->features); > > > > > clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf2127->rtc->features); > > > > > clear_bit(RTC_FEATURE_ALARM, pcf2127->rtc->features); > > > > > > > > > > -- > > > > > 2.35.1 > > > > > > > > > > > > > > > > > -- > > > > Hugo Villeneuve > > > > > > -- > > > Alexandre Belloni, co-owner and COO, Bootlin > > > Embedded Linux and Kernel engineering > > > https://bootlin.com > > > > > > > > > -- > > Hugo Villeneuve > > -- > Alexandre Belloni, co-owner and COO, Bootlin > Embedded Linux and Kernel engineering > https://bootlin.com > -- Hugo Villeneuve