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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 58A97C0219D for ; Thu, 13 Feb 2025 12:57:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=YBQYwQdRIQ20yozFfxJGyrrPezD83gPdJ94AG2odwmc=; b=Pnz91dvBtbK5h4tc3nXM0X5u9I rjZ6sFNvVoDuC/ilAtLd8vmxNTW0X5pEsnEJTHU5T8M3Na7l8ZSu2NamqB55qrAZX2S3OwcZhUqU0 oVAL07A+yMYFluxugKIixqpGYpwGj/9axv081BtBK65hvaw+zYAkOgfIVS5wCQD+DeXWb5IO8vrEU wRSxNFw3IqlkhIjCrU2ivZYE8cRUPNgdkmuSnupb+fgV3oIXw9hQ3Xj1x+CDJLX1gt8xaQ2z/i9Ky 1Z4TdFkVmiLb48wcvzF4V9EgrRP9D75ZLjTS2GCUyK0M20+ym6zZJGtLIVwAwR6bDa4sRa0LiY3Gb fXmCqNeQ==; 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charset=us-ascii Content-Disposition: inline In-Reply-To: <20250213133550.GA1208@localhost.localdomain> X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdegieekvdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepfffhvfevuffkfhggtggujgesthdtredttddtvdenucfhrhhomheptehlvgigrghnughrvgcuuegvlhhlohhnihcuoegrlhgvgigrnhgurhgvrdgsvghllhhonhhisegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeegieduueethefhkeegjeevfefhiedujeeuhffgleejgfejgeekueejuefgheeggfenucffohhmrghinhepsghoohhtlhhinhdrtghomhenucfkphepvdgrtddumegtsgdugeemheehieemjegrtddtmegukeejvgemudgsudgsmeeltdekgeemtggtfhgtnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepvdgrtddumegtsgdugeemheehieemjegrtddtmegukeejvgemudgsudgsmeeltdekgeemtggtfhgtpdhhvghloheplhhotggrlhhhohhsthdpmhgrihhlfhhrohhmpegrlhgvgigrnhgurhgvrdgsvghllhhonhhisegsohhothhlihhnrdgtohhmpdhnsggprhgtphhtthhopedufedprhgtphhtthhopehpvghnghdrfhgrnhesohhsshdrnhigphdrtghomhdprhgtphhtthhopehsuhguvggvphdrhhholhhlrgesrghrmhdrtghomhdprhgtphhtthhopehpvghnghdrf hgrnhesnhigphdrtghomhdprhgtphhtthhopegtrhhishhtihgrnhdrmhgrrhhushhsihesrghrmhdrtghomhdprhgtphhtthhopehshhgrfihnghhuoheskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepshdrhhgruhgvrhesphgvnhhguhhtrhhonhhigidruggvpdhrtghpthhtohepkhgvrhhnvghlsehpvghnghhuthhrohhnihigrdguvgdprhgtphhtthhopehfvghsthgvvhgrmhesghhmrghilhdrtghomh X-GND-Sasl: alexandre.belloni@bootlin.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250213_045448_593045_ABA31397 X-CRM114-Status: GOOD ( 13.02 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 13/02/2025 21:35:50+0800, Peng Fan wrote: > >Well, yes, you have your answer here, if the firmware knows RTC1 is more > >accurate and will be your source of truth, then simply use this one. > > But issue is RTC1 is only readable to Linux non-safety, Linux not able > to set alarm. Linux could only use RTC0 for alarm with current i.MX95 EVK > firmware. > > If RTC1 could be exported to linux for control, we could for sure > switch to using RTC1 without caring about RTC0. But this is not true. > > RTC0 is free for linux to control, RTC1 not. Switching to RTC1 will make > us lose RTC alarm to wake up linux feature. > This doesn't make any sense, this limitation is on your firmware side, either RTC1 has alarm support and the firmware can set the alarm for linux or it doesn't and then, the firmware must set the time and alarm on RTC0. -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com