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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 432A4C433EF for ; Tue, 19 Jul 2022 14:21:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239445AbiGSOPV (ORCPT ); Tue, 19 Jul 2022 10:15:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236940AbiGSON7 (ORCPT ); Tue, 19 Jul 2022 10:13:59 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 8F4E8599E1 for ; Tue, 19 Jul 2022 06:39:35 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CE352153B; Tue, 19 Jul 2022 06:39:35 -0700 (PDT) Received: from bogus (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8F01D3F766; Tue, 19 Jul 2022 06:39:33 -0700 (PDT) Date: Tue, 19 Jul 2022 14:39:31 +0100 From: Sudeep Holla To: Saravana Kannan Cc: Marek Szyprowski , Sudeep Holla , Russell King , Philipp Zabel , Rob Herring , Ulf Hansson , John Stultz , Linus Walleij , Nicolas Saenz Julienne , Geert Uytterhoeven , Kefeng Wang , kernel-team@android.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4] amba: Remove deferred device addition Message-ID: <20220719133931.7dkcejvc6s4a7y4z@bogus> References: <20220705083934.3974140-1-saravanak@google.com> <7482d3af-4b02-4c1d-0386-b0a4ddf529da@samsung.com> <8a04332e-e7b1-8bc3-d569-5052427bcb13@samsung.com> <20220713145827.yxeoqj6vmkzhrrpv@bogus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 18, 2022 at 06:55:23PM -0700, Saravana Kannan wrote: > On Wed, Jul 13, 2022 at 7:58 AM Sudeep Holla wrote: > > > > On Tue, Jul 12, 2022 at 12:38:33PM -0700, Saravana Kannan wrote: > > > Sudeep, > > > > > > This makes me think the issue you are seeing is related to your > > > hardware drivers. Can you look into those please? I'm leaning towards > > > merging this amba clean up and adding delays (say 1ms) to your > > > clock/power domain drivers to avoid the crash you are seeing. And then > > > you can figure out the actual delays needed and update it. > > > > I haven't got a chance to debug the issue on Juno much further. One thing > > about the platform is that we can't turn off the debug power domain that > > most of the coresight devices share. > > > > One thing I also observed with -next+this patch is that with a little log > > it can access the registers while adding first few devices and then crash > > which doesn't align with platform behaviour as we can't turn off the domain > > though we attached and turn on in amba_read_periphid and then turn off and > > detach the power domain. Ideally if first device amba_read_periphid was > > successful, it must be the case for all, but I see different behaviour. > > > > I need to check again to confirm if it is issue with platform power domain > > driver. It is based on SCMI so there is some role played by the f/w as well. > > Yeah, this log timing based behavior is what makes me suspect it's not > a problem with this patch itself. > > However, just to rule it out, can you try making this change on top of > v4 and give it a shot? This is related to the issue Marek reported, > but those are more about permanent probe failures. Not a crash. > This patch(version v4, fails to apply on -next but the conflict is trivial and in the deleted code so I just retained your copy of all the functions) plus the below change fixes the issue I reported on Juno. I won't give you tested-by yet as you have plans to revert some things and I resolved the conflict here though trivial, I prefer to apply the patch as is with all associated changes and test once more. Thanks for digging this and fixing it. -- Regards, Sudeep