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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8AC9C433DF for ; Thu, 14 May 2020 16:34:48 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A8A362065D for ; Thu, 14 May 2020 16:34:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="MSdTi25o"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="UvPlZl0i" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A8A362065D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=GZahyAYATA2Ej7Vl0ID4yWkKUVgKRlxABcCzk0LeHG0=; b=MSdTi25olJnJjD 2TOUWHc0buBwHpe3A+dBVnsXmi8T1uREyJ7OYzv6rskcf+IOilZRvnWu0Ke1PCBoaVtb7V2H5z7CR zGdqwDSAfq9pa+IxhMrSAen/1f/QpNSOKt8aDNyao1mOVoMrsXTWI1xL1TRKfTpO3MRwXXk2PtJBh ufyq6SFpScaEkbsJldN9vgy+CW4UNFlqtVp1VgEi7s+RxQ3Rv1A2/isIwOypPCqmRWRMUxEtNg1Bz w6IRLQb+rxoVeutdhdiT/AMXUbBXzoOzjtjC+8Oi7l67lye2ty/2wEffN4BKd3hz72Ps9KSYQeukH G/S9dnnDznVnd7OJYceQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jZGop-0005M4-SV; Thu, 14 May 2020 16:34:47 +0000 Received: from mail-pg1-x541.google.com ([2607:f8b0:4864:20::541]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jZGok-0005Ld-Hk for linux-arm-kernel@lists.infradead.org; Thu, 14 May 2020 16:34:46 +0000 Received: by mail-pg1-x541.google.com with SMTP id j21so1456398pgb.7 for ; Thu, 14 May 2020 09:34:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=HWFeoUCCAGrwFNZxgc3//5BRvEIhNROwr+Wf1EbQfmY=; b=UvPlZl0iOaSxRCrz4fSlO6xyQ4m5RIN2qw1rZtiYNuvBFSSNHUv+z6jsScDG2JkoLZ 9KPzqq9Yz+Xek9thEBwb1hxG4RE2BMXein7EOEaNp8aruvGk13N+6glTTIgL7iBjci/B OvS5nH3CBDh2XG23YTlRN04vrysWYTmp0OAqk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=HWFeoUCCAGrwFNZxgc3//5BRvEIhNROwr+Wf1EbQfmY=; b=bc5vSLCht7fZO9+2MbIlRBT6M/xR82ZEr+tjnS7YRvkOv0ymhOJEBBorR7LvFA3kZX HTZTYSgxtxBaXYCQrU8TRlassr+8svoTqvhtcPKOjSo7wBkIfX9f0UdIRUmGCTAK+XWL JVUQ4TwHRtyCuSwR1AdaZRq+LjIOgdU5b+RBW1nwhxq2iWkZ6/CFwqHJ+nIal+bnY2Am csv6JSVknuQ39zvPnPdFY/D/AB2e5CQTqNKyRyoG3GE92T0XVdut7vxW1G72M2vSmoha xCOB0YVXbBoxKrrT/Xxkqhk6ZISPPyz4AYVONnTl3iQFMkgE99Cbp8rLMcZVJrwtO7HR iRgg== X-Gm-Message-State: AOAM530rUygnIB6KZdYgV+QGjyary7lMiApyBu/phJiUfzEx75timgxp dRVa2DUmOk+N7gR2nCV957nt+JIT4kA= X-Google-Smtp-Source: ABdhPJy7n3o+fLD6OrDbmUtG9JAiyI0yMYYVbyEfxMc8X3njIGUu1jxmPBy8jh7CoHgFIwEEsV9a7Q== X-Received: by 2002:a63:b146:: with SMTP id g6mr4630780pgp.396.1589474081576; Thu, 14 May 2020 09:34:41 -0700 (PDT) Received: from mail-pl1-f174.google.com (mail-pl1-f174.google.com. [209.85.214.174]) by smtp.gmail.com with ESMTPSA id cv21sm18730032pjb.23.2020.05.14.09.34.39 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 14 May 2020 09:34:40 -0700 (PDT) Received: by mail-pl1-f174.google.com with SMTP id g11so1369633plp.1 for ; Thu, 14 May 2020 09:34:39 -0700 (PDT) X-Received: by 2002:a67:bd07:: with SMTP id y7mr4374233vsq.109.1589474077707; Thu, 14 May 2020 09:34:37 -0700 (PDT) MIME-Version: 1.0 References: <20200507200850.60646-1-dianders@chromium.org> <20200514162109.6qt5drd27hpilijh@holly.lan> In-Reply-To: <20200514162109.6qt5drd27hpilijh@holly.lan> From: Doug Anderson Date: Thu, 14 May 2020 09:34:26 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v4 00/12] kgdb: Support late serial drivers; enable early debug w/ boot consoles To: Daniel Thompson , Greg Kroah-Hartman , Will Deacon , Catalin Marinas X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200514_093442_589857_9DDCD76A X-CRM114-Status: GOOD ( 29.34 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-doc@vger.kernel.org, kgdb-bugreport@lists.sourceforge.net, Bjorn Andersson , "H. Peter Anvin" , Mauro Carvalho Chehab , Frank Rowand , Jonathan Corbet , x86@kernel.org, Russell King , Krzysztof Kozlowski , jinho lim , Andy Gross , Pawan Gupta , Linux ARM , linux-serial@vger.kernel.org, Jiri Slaby , Dave Martin , Masami Hiramatsu , linux-arm-msm , Alexios Zavras , bp@alien8.de, Thomas Gleixner , Ingo Molnar , Allison Randal , Juergen Gross , Sumit Garg , LKML , James Morse , "Eric W. Biederman" , Jason Wessel , Andrew Morton , Enrico Weigelt Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, On Thu, May 14, 2020 at 9:21 AM Daniel Thompson wrote: > > On Thu, May 07, 2020 at 01:08:38PM -0700, Douglas Anderson wrote: > > > > > > My first attempt was to try to get the existing "ekgdboc" to work > > earlier. I tried that for a bit until I realized that it needed to > > work at the tty layer and I couldn't find any serial drivers that > > managed to register themselves to the tty layer super early at boot. > > The only documented use of "ekgdboc" is "ekgdboc=kbd" and that's a bit > > of a special snowflake. Trying to get my serial driver and all its > > dependencies to probe normally and register the tty driver super early > > at boot seemed like a bad way to go. In fact, all the complexity > > needed to do something like this is why the system already has a > > special concept of a "boot console" that lives only long enough to > > transition to the normal console. > > > > > > > > The devices I had for testing were: > > - arm32: rk3288-veyron-jerry > > - arm64: rk3399-gru-kevin > > - arm64: qcom-sc7180-trogdor (not mainline yet) > > > > These are the devices I tested this series on. I tried to test > > various combinations of enabling/disabling various options and I > > hopefully caught the corner cases, but I'd appreciate any extra > > testing people can do. Notably I didn't test on x86, but (I think) I > > didn't touch much there so I shouldn't have broken anything. > > I have tested a slightly earlier version using qemu and will test this > set before it moves forwards. > > > > .../admin-guide/kernel-parameters.txt | 20 ++ > > Documentation/dev-tools/kgdb.rst | 24 ++ > > arch/arm64/Kconfig | 1 + > > arch/arm64/include/asm/debug-monitors.h | 2 + > > arch/arm64/kernel/debug-monitors.c | 2 +- > > arch/arm64/kernel/traps.c | 3 + > > arch/x86/Kconfig | 1 + > > drivers/tty/serial/8250/8250_early.c | 23 ++ > > drivers/tty/serial/amba-pl011.c | 32 +++ > > drivers/tty/serial/kgdboc.c | 268 ++++++++++++++++-- > > drivers/tty/serial/qcom_geni_serial.c | 32 +++ > > include/linux/kgdb.h | 4 + > > kernel/debug/debug_core.c | 52 +++- > > lib/Kconfig.kgdb | 18 ++ > > 14 files changed, 436 insertions(+), 46 deletions(-) > > Any thoughts on how best to land these changes? > > AFAICT the arm64 I was hoping to get an Ack from Will or Catalin for my most recent arm64 patch [1] and then it could land in your tree. However, it wouldn't be the end of the world if that landed later. "kgdbwait" would be broken if you used it together with "kgdb_earlycon" but overall we'd still be in a better place than we were. > and 8250/amba-pl011/qcom_geni_serial code > could be applied independently of the kgdb changes Right, that would be OK. Nobody would actually be able to use "kgdb_earlycon" until those landed but there would be no problem with those two landing separately. > (though we must keep > changes to drivers/tty/serial/kgdboc alongside the kgdb changes). > > I can hoover them up but I'd need a solid set of acks and > I don't think we've got that yet. It would be nice for it to be explicit, but "get_maintainer" says that Greg KH is the maintainer of serial drivers. Git log confirms that he also has been the one landing changes to these files. Early-on he provided his Reviewed-by for the series as a whole, so he's aware of it and maybe would be fine w/ the serial changes landing through the kgdb tree? Greg: is that correct? > I'd also be happy to ack where needed and let someone else pick it up > (the other changes queued for kgdb this cycle are pretty small so we > shouldn't see much conflict in kernel/debug/ ). It feels to me that the kgdb tree is the best destination for all these patches if possible. [1] https://lore.kernel.org/r/20200513160501.1.I0b5edf030cc6ebef6ab4829f8867cdaea42485d8@changeid -Doug _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel