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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 DF67DC49ED7 for ; Fri, 13 Sep 2019 03:42:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A65CB2084D for ; Fri, 13 Sep 2019 03:42:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568346144; bh=a4+pLs0HMpwthQVTXKUFl9IjvLrN/5bYwSFxfU5uDKw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=kAMizI+7fcynRH8iBWfyfR0jlNm71DHMv4iFJtzKl5sehozw2lZcTu0+Mv4NyZNMT i39lfsx86P3/IIwIBskanZ79adIBYg2EC0L/NI3wyUIPEWXpyO5785Tut3n71Ht3+u NM269ly0LlC/EVpgpnQA0FbdM/NdOsaPw/YP7+MQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728080AbfIMDmY (ORCPT ); Thu, 12 Sep 2019 23:42:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:59626 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728062AbfIMDmX (ORCPT ); Thu, 12 Sep 2019 23:42:23 -0400 Received: from dragon (98.142.130.235.16clouds.com [98.142.130.235]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 759EF20684; Fri, 13 Sep 2019 03:42:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568346143; bh=a4+pLs0HMpwthQVTXKUFl9IjvLrN/5bYwSFxfU5uDKw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=iTlc+yhvbhgGcqvpGhGuRb8jZA11MoghlvglMSEwsgxqcp05bmmYUKE/J82jv2Buq pkUX/gLzFxBDpIjNUXXObPjP/a7HDnHC26YmztmstpVsv6dzCD2EJ3XkWgwe1+vVFo gn5lk9BdxbneE1Q+HqWQtNKWa8WvzoHclgfl9gLk= Date: Fri, 13 Sep 2019 11:42:14 +0800 From: Shawn Guo To: Anson Huang Cc: Dong Aisheng , Stephen Boyd , Peng Fan , "festevam@gmail.com" , "mturquette@baylibre.com" , "s.hauer@pengutronix.de" , Aisheng Dong , "kernel@pengutronix.de" , dl-linux-imx , Jacky Bai , Abel Vesa , "linux-clk@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] clk: imx: lpcg: write twice when writing lpcg regs Message-ID: <20190913034213.GH17142@dragon> References: <1566936978-28519-1-git-send-email-peng.fan@nxp.com> <20190906172044.B99FB20838@mail.kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org On Tue, Sep 10, 2019 at 02:47:59AM +0000, Anson Huang wrote: > > > > On Sat, Sep 7, 2019 at 9:47 PM Stephen Boyd wrote: > > > > > > Quoting Peng Fan (2019-08-27 01:17:50) > > > > From: Peng Fan > > > > > > > > There is hardware issue that: > > > > The output clock the LPCG cell will not turn back on as expected, > > > > even though a read of the IPG registers in the LPCG indicates that > > > > the clock should be enabled. > > > > > > > > The software workaround is to write twice to enable the LPCG clock > > > > output. > > > > > > > > Signed-off-by: Peng Fan > > > > > > Does this need a Fixes tag? > > > > Not sure as it's not code logic issue but a hardware bug. > > And 4.19 LTS still have not this driver support. > > Looks like there is an errata for this issue, and Ranjani just sent a patch for review internally, Having errata number in both commit log and code comment is generally helpful. Shawn