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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 1969AC433F5 for ; Tue, 14 Sep 2021 16:44:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDB72610A6 for ; Tue, 14 Sep 2021 16:44:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229975AbhINQpV (ORCPT ); Tue, 14 Sep 2021 12:45:21 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:41072 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229448AbhINQpT (ORCPT ); Tue, 14 Sep 2021 12:45:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=n6CAK2ehnhV5D05PFbTpVXv8GW58kVhsKzx/9xBlgbw=; b=YtvEUTDvdgQVZL7zt/8QUe4Ad6 E+vOcMKr33Yxv5tZ/9x3bLPCnKLaJlj9Jr/26HWLKSp0ii0o1rCvoNXCpoFyruWvWDhNSuyMxEMXF 0C3yiCmTY52QBhtbUuzH/m1CgGKRBoIIWgDPsywSj8JjQ3hZbej80WZaX+Zyb0IqCevM=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1mQBXE-006cqY-EE; Tue, 14 Sep 2021 18:43:52 +0200 Date: Tue, 14 Sep 2021 18:43:52 +0200 From: Andrew Lunn To: Saravana Kannan Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , John Stultz , Marek Szyprowski , Rob Herring , Geert Uytterhoeven , Vladimir Oltean , kernel-team@android.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 5/5] driver core: Add fw_devlink.debug command line boolean parameter Message-ID: References: <20210914043928.4066136-1-saravanak@google.com> <20210914043928.4066136-6-saravanak@google.com> 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 > I did think of this, but the problem is that dynamic debug logs can > get compiled out (when DYNAMIC_DEBUG isn't set). I think debugging of > fw_devlink needs to be possible without having to recompile the > kernel. So in a sense similar to how initcall_debug works today. My off the shelf Debian kernel has it enabled. Maybe you can check other mainline distributions and see if it is enabled by default. You are also on a slippery path. You argue this is needed all the time and add a custom knob. Somebody else adds a new feature which they also argue always needs bug, and add there own custom knob. We soon have lots of custom knobs, each doing it slightly differently, in different places. Chaos. So you need a really good argument why your code really is special. I would suggest you start with dynamic debug, and collect some statistics of how often you need to ask people to recompile their kernel. Andrew