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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 E01E5C433ED for ; Mon, 3 May 2021 18:00:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ACE0661244 for ; Mon, 3 May 2021 18:00:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231378AbhECSBv (ORCPT ); Mon, 3 May 2021 14:01:51 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:48694 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230113AbhECSBs (ORCPT ); Mon, 3 May 2021 14:01:48 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1620064853; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ybWEm0mGIHCtz87WK8S5IqBOn19onecVqJzpzLBEw3A=; b=KWutC8Xr0/O9okcisl5YFwXzc3Xz+TBFCGIQUoWGFF8Cku1LVRyE/kY5hjmHZnC3WjYxpP GC/JgwYeOMW0lLXgQwJAyWtXnRtcKVBlYFTd5AqB7XLfG/IzUBxjWlCJCS/cBKMY/LUJPM Vbi6qKIQL/YqYMa3Cu9MOEvj638ZpH0rXPSbQV5D+z2hIDC09MRk+O+pnqkVuO+jpERk8D Sg6AFUTSd/prhIbBw6kUn6DAyITmT2IltzFXunPIbLvWNrEPx+1ugJ5gOLMCCvu8ZraeCw 7VbwfV7adYAhagPIgw5ADsFHbN9Jb13FKNkMd6+ACzXSB4cliZMKO63/YfNDdw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1620064853; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ybWEm0mGIHCtz87WK8S5IqBOn19onecVqJzpzLBEw3A=; b=auEY4YLz8LRn3xSUI0iBxneIrl1Xca0UgfKaIBqJtqeLbbeS7Vq6EqrmRC9nVAInvm8NJo V6j5oXwOG5gJfzCg== To: Alexandre Belloni Cc: John Stultz , Stephen Boyd , linux-kernel@vger.kernel.org Subject: Re: [PATCH] alarmtimer: check RTC features instead of ops In-Reply-To: References: <20210429214902.2612338-1-alexandre.belloni@bootlin.com> <877dkkfdif.ffs@nanos.tec.linutronix.de> <871rasf8qe.ffs@nanos.tec.linutronix.de> Date: Mon, 03 May 2021 20:00:53 +0200 Message-ID: <87wnsfd7e2.ffs@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 03 2021 at 17:34, Alexandre Belloni wrote: > On 30/04/2021 10:59:53+0200, Thomas Gleixner wrote: >> I'm even more confused. So RTC0 does not have .set_alarm() but why does >> it turn on RTC_FEATURE_ALARM? I'm obviously misinterpreting the above... >> > > I'm sorry for not being clear. > > With RTC0 not having alarms and RTC1 having alarms: > > The previous situation was: > > The driver for RTC0 didn't have any .set_alarm() to signel it doesn't > support alarms. > On registration, alarmtimer_rtc_add_device finds out it doesn't have the > .set_alarm() callback and doesn't select that RTC. > On registration of RTC1, alarmtimer_rtc_add_device finds .set_alarm() > and RTC1 is now the alarmtimer rtcdev. > > The new situation is: > > The driver for RTC0 always have .set_alarm() but clears > RTC_FEATURE_ALARM to signal it doesn't support alarms. > On registration, alarmtimer_rtc_add_device finds .set_alarm() and RTC0 > is now the alarmtimer rtcdev, leading to an error when rtc_timer_start() > is called. > > I hope this is clearer. Yes, that makes sense now!