Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755617AbcCCBlP (ORCPT ); Wed, 2 Mar 2016 20:41:15 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:58057 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755427AbcCCBlM (ORCPT ); Wed, 2 Mar 2016 20:41:12 -0500 Date: Wed, 2 Mar 2016 17:41:10 -0800 From: Stephen Boyd To: Srinivas Kandagatla Cc: Andy Gross , David Brown , Greg Kroah-Hartman , Jiri Slaby , linux-arm-msm@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tty: msm_serial: remove static clk rate setting in probe Message-ID: <20160303014110.GH24999@codeaurora.org> References: <1456831373-14839-1-git-send-email-srinivas.kandagatla@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1456831373-14839-1-git-send-email-srinivas.kandagatla@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1357 Lines: 38 On 03/01, Srinivas Kandagatla wrote: > The issue with setting up a fixed clock rate at probe is that it would > overwrite the console rate set by the bootloader for its console device. > This would result in serial out corruption or missing log when we system > is booted with earlycon. This is not a issue if we boot system without > earlycon. > > This setup is ateast not required with the mainline driver. at least? May be worth mentioning that this code used to be required because the clk_enable() call would fail if clk_set_rate() wasn't called first. > > Originally the issue was noticed on DB410c which is based on APQ8016 > chipset. > > Without this patch the console log with earlycon would look like: > ... > [ 0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=64, nr_cpu_ids=1 > [ 0.000000] NR_IRQS:64 nr_irqs:64 0 > ����+HH��0.699378] console [ttyMSM0] enabled > [ 0.699378] console [ttyMSM0] enabled > [ 0.702003] bootconsole [uart0] disabled > [ 0.702003] bootconsole [uart0] disabled > ... > > with this patch I can see all the skipped lines on the console > > Signed-off-by: Srinivas Kandagatla otherwise Reviewed-by: Stephen Boyd -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project