From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752584AbdFVDWJ (ORCPT ); Wed, 21 Jun 2017 23:22:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:60800 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752381AbdFVDWH (ORCPT ); Wed, 21 Jun 2017 23:22:07 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D58B021D2C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=robh@kernel.org MIME-Version: 1.0 In-Reply-To: References: <1497278211-5001-1-git-send-email-suzuki.poulose@arm.com> <1497278211-5001-2-git-send-email-suzuki.poulose@arm.com> <20170613165528.GA6392@xps15> <20170616180820.enc3hxpju2tfu3fg@rob-hp-laptop> From: Rob Herring Date: Wed, 21 Jun 2017 22:21:45 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 01/12] coresight replicator: Cleanup programmable replicator naming To: Mathieu Poirier Cc: Suzuki K Poulose , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Pratik Patel , "Ivan T . Ivanov" , "devicetree@vger.kernel.org" , Mark Rutland Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 20, 2017 at 11:44 AM, Mathieu Poirier wrote: > On 18 June 2017 at 08:04, Rob Herring wrote: >> On Tue, Jun 13, 2017 at 10:55:28AM -0600, Mathieu Poirier wrote: >>> On Mon, Jun 12, 2017 at 03:36:40PM +0100, Suzuki K Poulose wrote: >>> > The Linux coresight drivers define the programmable ATB replicator as >>> > Qualcom replicator, while this is designed by ARM. This can cause confusion >>> > to a user selecting the driver. Cleanup all references to make it >>> > explicitly clear. This patch : >>> > >>> > 1) Adds a new compatible string for the same, retaining the old one for >>> > compatibility. >>> > 2) Changes the Kconfig symbol (since this is not part of any defconfigs) >>> > CORESIGHT_QCOM_REPLICATOR => CORESIGHT_DYNAMIC_REPLICATOR >>> > 3) Improves the help message in the Kconfig. >>> > 4) Changes the name of the driver : >>> > coresight-replicator-qcom => coresight-dynamic-replicator >>> > >>> > Cc: Pratik Patel >>> > Cc: Ivan T. Ivanov >>> > Cc: Mathieu Poirier >>> > Cc: devicetree@vger.kernel.org >>> > Cc: Rob Herring >>> > Cc: Mark Rutland >>> > Signed-off-by: Suzuki K Poulose >>> >>> Hi Suzuki, >>> >>> > --- >>> > Documentation/devicetree/bindings/arm/coresight.txt | 4 +++- >>> > drivers/hwtracing/coresight/Kconfig | 10 +++++----- >>> > drivers/hwtracing/coresight/Makefile | 2 +- >>> > drivers/hwtracing/coresight/coresight-replicator-qcom.c | 2 +- >>> > 4 files changed, 10 insertions(+), 8 deletions(-) >>> > >>> > diff --git a/Documentation/devicetree/bindings/arm/coresight.txt b/Documentation/devicetree/bindings/arm/coresight.txt >>> > index fcbae6a..f77329f 100644 >>> > --- a/Documentation/devicetree/bindings/arm/coresight.txt >>> > +++ b/Documentation/devicetree/bindings/arm/coresight.txt >>> > @@ -34,7 +34,9 @@ its hardware characteristcs. >>> > - Embedded Trace Macrocell (version 4.x): >>> > "arm,coresight-etm4x", "arm,primecell"; >>> > >>> > - - Qualcomm Configurable Replicator (version 1.x): >>> > + - Coresight programmable Replicator (version 1.x): >>> > + "arm,coresight-dynamic-replicator", "arm,primecell"; >>> > + OR >>> > "qcom,coresight-replicator1x", "arm,primecell"; >>> >>> Rob, what's your view on keeping the old binding around? We could simply change >>> the two occurences we find in the DTs (Juno and 410c) to the new name and be >>> done with the old one. >> >> Juno uses the Qcom string? We should keep the old string. You can switch >> the dts files, but the driver should support the old name. > > When we first started working on CoreSight programmable replicators > were available but the documentation wasn't public. As such when I > saw Qualcomm's design I mistakenly thought it was a custom IP block > and came up with a compatible string that reflected that reality. > Fast forward 3 years the documentation is available and Juno has used > the same IP block in their design. Suzuki's patch rectifies history > by changing the programmable replicator naming convention to what it > should have been from the start. > > That being said, we can keep the old compatible string around but it > won't change anything. CoreSight devices are discovered on the AMBA > bus and don't use the compatible string - drivers are probed based on > AMBA IDs laid out in the drivers and device IDs found in HW ID > registers. > > In light of the above let me know what you want to do. Well, if drivers don't use the string, then there is nothing to keep around. Rob