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=-9.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 A35D0C433E1 for ; Thu, 20 Aug 2020 14:53:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7BA7A2075E for ; Thu, 20 Aug 2020 14:53:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597935237; bh=pSyLCSjLNaoL9qhpLxOpTdvEKBIbz4IpNwyffAy0eto=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=nuaN0d137yxMORm9f0aXE8vPuwP6tO/ReWjbWu0IINeUlQQLMQu01NlvbZ4tVOEH2 f1SU/cH82sgPXpBL/F9Du/56M1inOXHA9/PhzOyR44le4zOMegEk6ICUvcYRopv+lv Y8NEkJq4laHQTcRlYwuzSzb/eJuWcVCAvGUE5h6s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728105AbgHTOxz (ORCPT ); Thu, 20 Aug 2020 10:53:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:47998 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728058AbgHTOxm (ORCPT ); Thu, 20 Aug 2020 10:53:42 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 41AAF2075E; Thu, 20 Aug 2020 14:53:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597935221; bh=pSyLCSjLNaoL9qhpLxOpTdvEKBIbz4IpNwyffAy0eto=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=K87nPqzPK7zV2HjLW+4JGIe56cVVNM47n1uO+JdtyZzahMd4fCF9hYerAz6I5YYqa QNtTO5/sg6lDgORj+sVp3XVTjzak81uojvgFjx26rcdLkKfUmFhx0uPKuCay1Pphgx dspdb2jKjT4b7GG2zkDuDbDoX8pcO/i9YXeANkRg= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1k8lwh-004bi9-P2; Thu, 20 Aug 2020 15:53:39 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 20 Aug 2020 15:53:39 +0100 From: Marc Zyngier To: Saravana Kannan , Enric Balletbo i Serra Cc: Frank Wunderlich , LKML , Collabora Kernel ML , Frank Wunderlich , Matthias Brugger , Nicolas Boichat , Hsin-Yi Wang , Hanks Chen , Jason Cooper , Thomas Gleixner , linux-arm-kernel , "moderated list:ARM/Mediatek SoC support" Subject: Re: [PATCH] Revert "irqchip/mtk-sysirq: Convert to a platform driver" In-Reply-To: References: <20200819161907.1155110-1-enric.balletbo@collabora.com> User-Agent: Roundcube Webmail/1.4.7 Message-ID: <14b8f4b9667d29ee25e25eb19c69e3f7@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: saravanak@google.com, enric.balletbo@collabora.com, wichtig@fw-web.de, linux-kernel@vger.kernel.org, kernel@collabora.com, linux@fw-web.de, matthias.bgg@gmail.com, drinkcat@chromium.org, hsinyi@chromium.org, hanks.chen@mediatek.com, jason@lakedaemon.net, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-08-20 09:07, Saravana Kannan wrote: > On Thu, Aug 20, 2020 at 12:56 AM Marc Zyngier wrote: >> >> On 2020-08-19 19:51, Saravana Kannan wrote: >> > On Wed, Aug 19, 2020 at 9:52 AM Frank Wunderlich >> > wrote: >> >> >> >> hi, >> >> >> >> does the fix you've linked to my revert [1] not work in your case? >> >> >> >> [1] https://patchwork.kernel.org/patch/11718481/ >> > >> > Thanks for pointing it out Frank. Also, might want to avoid top >> > posting in the future. >> > >> > Enric, Can you please try that other fix and see if that solves your >> > issue? >> >> I think Enric was clear that the driver does probe correctly >> (meaning that he has the fix in his tree). It is everything else >> that breaks, because none of the drivers on the platform are >> equipped to defer their own probing. >> >> I think we need to change this works right now, meaning that we can't >> blindly change the behaviour of *built-in* drivers. I'll see if I can >> come up with something quickly, but I'll otherwise take Enric patch. > > Sounds fair Marc. > > Btw, Enric, out of curiosity, can you try adding "fw_devlink=on" to > your kernel command line to see if it helps? It basically ensures > proper probe ordering without depending on the drivers. There are some > corner cases where it still can't work properly (too much to explain > for a late night email), but if the platforms don't have those corner > cases it'll work perfectly. > > I'm fine with the revert if Marc isn't able to find a quick fix to the > drivers, but this might also fix your problem right away. I'm afraid there is no quick fix if we want to preserve the current behavior with built-in drivers, and not having "fw_devlink=on" by default makes it irrelevant for most people. fw_devlink also prevents my test platforms from booting (my rk3399 doesn't find its PCI devices with it), while the same kernel boots just fine without it. It could well be that the corner case is likely to be more prevalent than you seem to expect. I will probably end-up end-up queuing reverts for both mtk-sysirq, mtk-cirq, and qcom-pdc (the first two can't be built as module with mainline anyway, and I seem to remember that the latter caused some controversy as well). As an experiment, I have pushed out a branch[1] that implements a "hybrid" probe, retaining the previous early probe mechanism when the driver is built-in, and letting things rip when built as a module (if you do that, you hopefully know what you are doing). I'd welcome some testing on affected platforms (I don't have anything I can run mainline on that'd be affected). Thanks, M. [1] https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/log/?h=irq/hybrid-probe -- Jazz is not dead. It just smells funny...