From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay7-d.mail.gandi.net (relay7-d.mail.gandi.net [217.70.183.200]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 925266F31A for ; Thu, 30 May 2024 10:35:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717065337; cv=none; b=X8DWFZ7ELA8qNU8GjFbBB621RRkrTVtwpsUdWCxTqNze17bd9NfZNjQ0lpWtDO65xbSQ3v9jEPz8PB3htzXdK51+9Nk5//Pz4Ldmz+KYUFi5OaSIU9cGCLwdK1EIOYXJ/X9P5uY1GnJxsx4k78WyGZipZNJblp8wCbWkN0rA5m4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717065337; c=relaxed/simple; bh=pqbD0N1NVf3e0qDthV00G/3+lY3IaSKXBvkC+zTxL8E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hWfxMmdlInZXFPPS1W7fYnU2nfm41yKLfJBCXHx69S09jNkz5SITm45JHcXR4hyEgtIOQ+9C2exB9kD05dupA+ELBXiriU+uUOEzzC+8OhzVvAgfWchjhH89NumQyPei/gmr/fH42FMsvHEzrrcn25L9FopEuAZNBPA3YkT5UYo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=oAOy5YTr; arc=none smtp.client-ip=217.70.183.200 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="oAOy5YTr" Received: by mail.gandi.net (Postfix) with ESMTPSA id 7370B20007; Thu, 30 May 2024 10:35:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1717065332; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BZykNmxg7hR/8xc6u/yYo3ltmxTzxcq9jBsgTOcs6Og=; b=oAOy5YTrESsYOYx4ZW2wXReYowwOOJyLSRVbo0H+3GT11+s3U6f9bZ3oQX9ArUOORJ8Hne rEqNnPs2mzr73ETqj3Z72d7i08/sa7eMvgtjrLhpMaVag5RtJ8MV+5hlWE96X+gxML5S0Q bL9xHjrM07W7lsEzLO2Hj8C5BYEily281k8h4dGEda5EzsvVo+9AVgMLwz56GISVX4SGr+ yR+nOBbe0jMDMy9/dGM8WTcUr6JjBbW6qb3FO4EtVXlTvcoMDaeVDmdwlRzMGFTCPkqZ/3 tXz24404+FkX6vyG5UsRQhSyR1shCIf5XuWrfUVABNAn/Cfh3UEqxaG39xAYkg== Date: Thu, 30 May 2024 12:35:32 +0200 From: Alexandre Belloni To: =?iso-8859-1?B?Q3Pza+Fz?= Bence Cc: linux-rtc@vger.kernel.org Subject: Re: [PATCH 1/2] rtc: Add UIE handling ability to rtc_class_ops Message-ID: <20240530103532e6d4f421@mail.local> References: <20240528161314.404383-2-csokas.bence@prolan.hu> <202405281756543dfd3a39@mail.local> <81184944-5012-41da-a596-220b74437552@prolan.hu> Precedence: bulk X-Mailing-List: linux-rtc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <81184944-5012-41da-a596-220b74437552@prolan.hu> X-GND-Sasl: alexandre.belloni@bootlin.com On 30/05/2024 11:59:47+0200, Csókás Bence wrote: > Hi! > > On 5/28/24 19:56, Alexandre Belloni wrote: > > Hello, > > > > On 28/05/2024 18:13:14+0200, Csókás, Bence wrote: > > > Currently, Update Interrupt Enable is performed by emulating > > > it with either polling, or alarm interrupts. Some RTCs, however, > > > can directly provide Update Interrupts. > > > > > > > This has been removed from the kernel 13 years ago. What is your use > > case to reintroduce it? > > The rationale was in the cover letter. Currently, the RTC core uses the > alarm system to implement UI, but this causes lost updates on PCF2129. > However, it has built-in Update Interrupt capabilities in the form of the > Second Interrupt, therefore we should just use that. > > So my question would instead be: what was the rationale of removing it in > the first place? Well, you didn't answer my question which is why do you need UIE and especially UIE from the RTC? Using the timer emulation is probably what you want because it is in sync with your system time. -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com