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 8F20FC77B73 for ; Sat, 27 May 2023 08:20:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230320AbjE0IUw (ORCPT ); Sat, 27 May 2023 04:20:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50192 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229472AbjE0IUu (ORCPT ); Sat, 27 May 2023 04:20:50 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51138DE for ; Sat, 27 May 2023 01:20:49 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D8DF860AC0 for ; Sat, 27 May 2023 08:20:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83405C433EF; Sat, 27 May 2023 08:20:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685175648; bh=yGXj/vsNJ1iEb/Lh6DCbMWxe66a+oLeNV5+w6Nt9qBY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QSFUnZ2ez8FO3kEJiW2O9kPCmVgiSOIfnoR0/8zUmeqm1S+ExtQAfXBEyyGegtF8z TpQkTEC7qMZ5fSiERMMHr0MhI0CmHAPkmrBJI4xsmyjLPINvc9fWkZgjtEWB7HqvC4 Dh6w05YT0vmryoth/mDOvQyfJr72F7QnailqV9wo3X5T1OWq1IARgw8QUvtSD4bjvi hO+BaQK1hjPFJjxWLvCHyoFpGZfgZ+tcLQJN9bS9+ZfZRoCsA+uUMyUGu0Svnkg8gH b2OPcmQdiZ0tJXi5cAQduy8JckbXk4L+WS/IHNTvQszYIh0tRqHAd0JoRtRnLu9zHy K1jtTyxOE7FvA== Date: Sat, 27 May 2023 16:20:37 +0800 From: Shawn Guo To: Rasmus Villemoes Cc: "Peng Fan (OSS)" , s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Peng Fan Subject: Re: [PATCH V3] soc: imx: support i.MX93 soc device Message-ID: <20230527082037.GB528183@dragon> References: <20230515063730.2042715-1-peng.fan@oss.nxp.com> <33d57180-aa13-4178-86e1-c4cf6ef29a6e@prevas.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <33d57180-aa13-4178-86e1-c4cf6ef29a6e@prevas.dk> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 24, 2023 at 03:30:01PM +0200, Rasmus Villemoes wrote: > On 15/05/2023 08.37, Peng Fan (OSS) wrote: > > From: Peng Fan > > > > i.MX93 Device Unique ID(UID) is in eFuse that could be read through > > OCOTP Fuse Shadow Block. i.MX93 UID is 128 bits long, so introduce > > soc_uid_high to indicate the higher 64bits. > > So apparently, the imx8mp also has 128 bits, at least according to the > reference manual, which mentions a "UNIQUE_ID[127:64]" at offset 0xe00 - > 0xe10 (i.e. bank 40, words 0 and 1). > > However, no further mention of these upper bits can be found anywhere in > the RM, or in linux or u-boot, mainline or downstream NXP. Furthermore, > quick experiments on both an imx8mp-evk and a custom imx8mp board > reveals that those words are not locked down (they do seem to have some > contents from the factory, but I can still set more bits in them). > > Could someone from NXP please explain what exactly bank 40, words 0 and > 1, on imx8mp are for? What do their initial value mean, why are they not > locked down, and why does the RM indicate that they should be part of a > unique_id? > > Also, assuming that the RM is just wrong (wouldn't be the first time; > the description of the lower 64 bits is also wonky in its own special > way), an obvious follow-up question is: Are the currently exposed > (lower) 64 bits unique among all imx8mp SOCs, i.e. does those 64 bits by > themselves actually work as a uid? Rasmus, Are you fine with the patch itself? Or do you expect more clarification in the commit log? Shawn