From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH] tty: msm_serial: remove static clk rate setting in probe Date: Wed, 2 Mar 2016 17:41:10 -0800 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-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <1456831373-14839-1-git-send-email-srinivas.kandagatla@linaro.org> Sender: linux-arm-msm-owner@vger.kernel.org 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 List-Id: linux-serial@vger.kernel.org On 03/01, Srinivas Kandagatla wrote: > The issue with setting up a fixed clock rate at probe is that it woul= d > overwrite the console rate set by the bootloader for its console devi= ce. > This would result in serial out corruption or missing log when we sys= tem > is booted with earlycon. This is not a issue if we boot system withou= t > earlycon. >=20 > 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. >=20 > Originally the issue was noticed on DB410c which is based on APQ8016 > chipset. >=20 > Without this patch the console log with earlycon would look like: > ... > [ 0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=3D64, nr_c= pu_ids=3D1 > [ 0.000000] NR_IRQS:64 nr_irqs:64 0 > =EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD+HH=EF=BF=BD=EF=BF=BD0.699378] co= nsole [ttyMSM0] enabled > [ 0.699378] console [ttyMSM0] enabled > [ 0.702003] bootconsole [uart0] disabled > [ 0.702003] bootconsole [uart0] disabled > ... >=20 > with this patch I can see all the skipped lines on the console >=20 > Signed-off-by: Srinivas Kandagatla otherwise Reviewed-by: Stephen Boyd --=20 Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project