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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2E937C433E0 for ; Wed, 20 May 2020 08:32:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F2BA7207ED for ; Wed, 20 May 2020 08:32:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ioWZhImd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726839AbgETIcq (ORCPT ); Wed, 20 May 2020 04:32:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726224AbgETIcp (ORCPT ); Wed, 20 May 2020 04:32:45 -0400 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BCDFC061A0E; Wed, 20 May 2020 01:32:45 -0700 (PDT) Received: by mail-pg1-x544.google.com with SMTP id s10so1117264pgm.0; Wed, 20 May 2020 01:32:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=LdXCTub4Z9kDMOSy0ARQdskJN6lbu+XKJdQ8G1oxt2w=; b=ioWZhImdJDpldT4SXJ9FDSvyluvAVlamd6Z0TPO1ZCr3WXm+XVbBYF9lRlMTGfKiKP fwn6gWXg/dMeYxmVmC6VCbCS813r3sF8ENw447F9cDZN7o+4jwf/ATR4C4xfJlmDxPr6 VvHSR5zXvxwrCQdrSC+eNGxlXV8KtMFitR4k98f+Y0AFsYmu9xI/EeJblOAhUJIrQ5ti HTZW/41UyGeg1taV1I3LZpMGDmng67TjVIn+9Hs+NVuh39gvBCX9vwCElmWiHsoRqEtd arPVZp8aD9G1ASHPX4AFLYDGOMNVtJ61wePi0FfgHxsfz80qD6WMxu2KD0EaSyqsNnzG iDww== 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=LdXCTub4Z9kDMOSy0ARQdskJN6lbu+XKJdQ8G1oxt2w=; b=C3l8BkhOJdmvflCPcVPjjshjZCKson+EJG8NP7+WTBU7exZ5yOPh2OJHtRjjviSRT6 s3TXMBJGcKzY798r0sxwCslebdjTpXaVQdVx1Y1QSHcIBKQIq+XC8z2+ookjvNrlXxZE yiDZfhaddE+jPu+UxL3G1I4ofDJ+x44uHMC7XYHuj6820TSiRGNexJDrGQbJo8OZWLwl boiUJmOll9o1vO3oPacxgplKyvJJixOsFYd14DTdtNy83rICsfqo+5k/UNFz2Rqg1x1t 066HnRZ3HZkudM9mbCja/Uygrzat/SxCpojKio+U5w3BxkIilH9NGbpSLTf7N3nnsN2P GINg== X-Gm-Message-State: AOAM530Wb8RToELmJqzR3FBKQR9ahXBX+MUO+a0h6H3+/g+UYGHisNJC WE9omyaJF/AkZN2wshbmrDfiFpN5xB0aFPKrh+M= X-Google-Smtp-Source: ABdhPJxyc7lGecCf47GbjoOmrlktPAZ4hEbvxvpm/3E/o9ZhCs/tLKv3L7khmH+4TruBr0WdnFND/2t3RPZbLKPE2F0= X-Received: by 2002:a65:6251:: with SMTP id q17mr3051810pgv.4.1589963564573; Wed, 20 May 2020 01:32:44 -0700 (PDT) MIME-Version: 1.0 References: <20200515212846.1347-1-mcgrof@kernel.org> <20200515212846.1347-13-mcgrof@kernel.org> <2b74a35c726e451b2fab2b5d0d301e80d1f4cdc7.camel@sipsolutions.net> <7306323c35e6f44d7c569e689b48f380f80da5e5.camel@sipsolutions.net> <20200519140212.GT11244@42.do-not-panic.com> In-Reply-To: From: Andy Shevchenko Date: Wed, 20 May 2020 11:32:32 +0300 Message-ID: Subject: Re: [PATCH v2 12/15] ath10k: use new module_firmware_crashed() To: Emmanuel Grumbach Cc: Brian Norris , Luis Chamberlain , Johannes Berg , linux-wireless , aquini@redhat.com, "Peter Zijlstra (Intel)" , Daniel Vetter , Mauro Carvalho Chehab , Will Deacon , Baoquan He , ath10k@lists.infradead.org, Takashi Iwai , Ingo Molnar , Dave Young , Petr Mladek , Kees Cook , Arnd Bergmann , gpiccoli@canonical.com, Steven Rostedt , cai@lca.pw, Thomas Gleixner , Andy Shevchenko , Kalle Valo , "" , schlad@suse.de, Linux Kernel , Jessica Yu , Andrew Morton , "David S. Miller" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 20, 2020 at 8:40 AM Emmanuel Grumbach wrote: > Since I have been involved quite a bit in the firmware debugging > features in iwlwifi, I think I can give a few insights here. > > But before this, we need to understand that there are several sources of issues: > 1) the firmware may crash but the bus is still alive, you can still > use the bus to get the crash data > 2) the bus is dead, when that happens, the firmware might even be in a > good condition, but since the bus is dead, you stop getting any > information about the firmware, and then, at some point, you get to > the conclusion that the firmware is dead. You can't get the crash data > that resides on the other side of the bus (you may have gathered data > in the DRAM directly, but that's a different thing), and you don't > have much recovery to do besides re-starting the PCI enumeration. > > At Intel, we have seen both unfortunately. The bus issues are the ones > that are trickier obviously. Trickier to detect (because you just get > garbage from any request you issue on the bus), and trickier to > handle. One can argue that the kernel should *not* handle those and > let this in userspace hands. I guess it all depends on what component > you ship to your customer and what you customer asks from you :). Or the two best approaches: 1) get rid of firmware completely; 2) make it OSS (like SOF). I think any of these is a right thing to do in long-term perspective. How many firmwares average computer has? 50? 100? Any of them is a burden and PITA. -- With Best Regards, Andy Shevchenko