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 E605DC54EAA for ; Fri, 27 Jan 2023 15:59:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232493AbjA0P75 (ORCPT ); Fri, 27 Jan 2023 10:59:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234501AbjA0P7k (ORCPT ); Fri, 27 Jan 2023 10:59:40 -0500 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 329DC8661F; Fri, 27 Jan 2023 07:59:19 -0800 (PST) Received: (Authenticated sender: alexandre.belloni@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id 076C4FF80D; Fri, 27 Jan 2023 15:59:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1674835152; 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=RwUvyQY9yRU9Kps/tTQepr1PT3uk85OHb20x3oTLZeE=; b=H8V67OhRZxSoFiHjZbsrUqofjNWKaI8I5plOXWne5ntYSeawDb7JbPcU5mzIu38NiKs8Nz Tuijj7CgTKJ3GUTNvF3xdCd3Pwvwx9R4TqSmtln/PpSQD+IKPki1gVvVXKjH4VHAEBqu06 Bfx79Qj4IkG7MYunWVQJElwUG33JdJNTWQucc8mjJ9fKdyxnss+O3jShAdURfpyIZqspyY cVBj+ReQxmvQSBxBGAt9iBP8B0wQQsdZBz77XzgS+2pCErbjQMgYl/PMwlltA06+Or8vek 5RklEXrtEelCkUlTeM935v28bpRT417JmFcVzS9vpBWwQqQJgPVg7PHjNp216Q== Date: Fri, 27 Jan 2023 16:59:10 +0100 From: Alexandre Belloni To: Johan Hovold Cc: Johan Hovold , Bjorn Andersson , Andy Gross , Konrad Dybcio , Alessandro Zummo , Rob Herring , Krzysztof Kozlowski , Maximilian Luz , linux-arm-msm@vger.kernel.org, linux-rtc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 19/24] rtc: pm8xxx: add support for uefi offset Message-ID: References: <20230126142057.25715-1-johan+linaro@kernel.org> <20230126142057.25715-20-johan+linaro@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27/01/2023 16:26:26+0100, Johan Hovold wrote: > On Fri, Jan 27, 2023 at 04:19:18PM +0100, Alexandre Belloni wrote: > > On 26/01/2023 15:20:52+0100, Johan Hovold wrote: > > > On many Qualcomm platforms the PMIC RTC control and time registers are > > > read-only so that the RTC time can not be updated. Instead an offset > > > needs be stored in some machine-specific non-volatile memory, which the > > > driver can take into account. > > > > > > Add support for storing a 32-bit offset from the GPS time epoch in a > > > UEFI variable so that the RTC time can be set on such platforms. > > > > > > > Why are you using the GPS epoch? This seems pretty random. > > Tell that to the Qualcomm firmware team. ;) > > Perhaps I could have made it more clear, but this is the format that the > firmware uses so Linux is not free to pick a different base here (or > time would differ ten years between UEFI/Windows and Linux). I expected this answer so please add this to the commit message, this will be the fifth epoch we ave to handle then... > > > > The UEFI variable is > > > > > > 882f8c2b-9646-435f-8de5-f208ff80c1bd-RTCInfo > > > > > > and holds a 12-byte structure where the first four bytes is a GPS time > > > offset in little-endian byte order. > > Johan -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com