From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755072AbcBWTEE (ORCPT ); Tue, 23 Feb 2016 14:04:04 -0500 Received: from mail-oi0-f49.google.com ([209.85.218.49]:35580 "EHLO mail-oi0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755033AbcBWTD6 (ORCPT ); Tue, 23 Feb 2016 14:03:58 -0500 Date: Tue, 23 Feb 2016 13:03:56 -0600 From: Andy Gross To: Georgi Djakov Cc: Srinivas Kandagatla , devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: dts: msm8916: Move smem below hwlock Message-ID: <20160223190356.GA17346@hector.attlocal.net> References: <1456248071-30547-1-git-send-email-georgi.djakov@linaro.org> <56CC970B.4080602@linaro.org> <56CCA95C.9070207@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <56CCA95C.9070207@linaro.org> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 23, 2016 at 08:47:56PM +0200, Georgi Djakov wrote: > On 23.02.16 г. 19:29, Srinivas Kandagatla wrote: > > > > > > On 23/02/16 17:21, Georgi Djakov wrote: > >> When the SMEM is probed it defers as it depends on the hardware lock, which > >> is not available yet. But the SMD bus and RPM regulators and clocks depend > >> on SMEM and they defer too. The problem with this is that the order of > >> registering the devices is not optimal and also we may end with messed > >> up serial console as the RPM clocks are not registered yet.. > > I noticed the same issue but was wondering why would we end up with messed up serial console? > > > > Could you add more details on why serial console is messed up? > > > > I thought, serial driver has nothing to do with the rpm clocks directly! > > > > If we don't have the rpm clocks registered, the uart clock is an orphan > and when clk_get_rate() is called on orphan clocks it returns 0 as rate. > In our case the msm_serial driver calls clk_get_rate() and gets 0 rate > as the parent rpm clock has not registered yet. The result is that the > baudrate is set incorrectly. This isn't a probe defer issue w/ the SMEM and hwspinlock. That works properly. This is an issue with the msm_serial either not probe deferring to wait for the rpm clocks or not handling the case of the clk framework giving us a 'bogus' clock. Can we queue off the clk_get_rate being 0 to probe defer for the rpm clocks? (although that is hacky). Regards, Andy