From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: [PATCH v3 3/4] driver core: add dev_print_hex_dump() logging function. Date: Mon, 8 Apr 2019 15:07:36 +0300 Message-ID: <20190408120736.GN9224@smile.fi.intel.com> References: <20190327014807.7472-1-ronald@innovation.ch> <20190327014807.7472-4-ronald@innovation.ch> <20190327023757.GB20766@kroah.com> <20190328002817.GF24753@innovation.ch> <20190328052917.GB18668@kroah.com> <20190328102755.GA26446@innovation.ch> <20190328112952.GA2232@kroah.com> <20190402024714.GA14213@innovation.ch> <20190402063326.GB7218@kroah.com> <20190407014613.GA14812@innovation.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20190407014613.GA14812@innovation.ch> Sender: linux-kernel-owner@vger.kernel.org To: "Life is hard, and then you die" Cc: Greg Kroah-Hartman , Dmitry Torokhov , Henrik Rydberg , Sergey Senozhatsky , Steven Rostedt , "Rafael J. Wysocki" , Lukas Wunner , Federico Lorenzi , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-input@vger.kernel.org On Sat, Apr 06, 2019 at 06:46:13PM -0700, Life is hard, and then you die wrote: > > On Mon, Apr 01, 2019 at 07:47:14PM -0700, Life is hard, and then you die wrote: > > > On Thu, Mar 28, 2019 at 12:29:52PM +0100, Greg Kroah-Hartman wrote: > > > > On Thu, Mar 28, 2019 at 03:27:55AM -0700, Life is hard, and then you die wrote: > > > > > On Thu, Mar 28, 2019 at 06:29:17AM +0100, Greg Kroah-Hartman wrote: > > > > > > On Wed, Mar 27, 2019 at 05:28:17PM -0700, Life is hard, and then you die wrote: > > > > > > > On Wed, Mar 27, 2019 at 11:37:57AM +0900, Greg Kroah-Hartman wrote: > > > > > > > > On Tue, Mar 26, 2019 at 06:48:06PM -0700, Ronald Tschalär wrote: > > You can do dynamic debugging from the kernel command line, if your code > > is built into the kernel (but why would a tiny driver under testing like > > this, not be built into the kernel?) what specifically did not work for you? > > This may be part of our disconnect: there's almost no reason (and > several downsides) to building it into the kernel instead of as a > module: > > - When developing, being able to just reload the module instead of > rebooting is just so much faster and more convenient. modprobe -r foo modprobe foo dyndbg=... Not an argument. > - For other users, having them build the driver as a dkms managed > module is also by far the simplest and least error-prone approach - > explaning to users how to rebuild their kernel (something most of > them have never done) takes a bunch of time and effort on both > sides for essentially no gain. > > - Once the driver is part of the regular kernel, practically all > distro's will build it as a module (at least I'm fairly certain > about this). Above seems a sub-items to the first one. So, reloading module with dyndbg parameter is quite flexible. What else? > > You can enable/disable logging per-function, which is what you want, > > right? > > Yes'ish: the problem is that if they are just part of regular > functions, A) the chances are higher that the function may get renamed > and hence any existing debug instructions broken, and B) this doesn't > work if there are multiple debug statements in a function. Hence my > assertion that for this work well (and yes, it can work well) you > basically need to create a separate function for each debug statement > (which that contains just that debug statement) (a sort of stable > labelling of each debug statement). I guess you tried and have an examples? -- With Best Regards, Andy Shevchenko