From mboxrd@z Thu Jan 1 00:00:00 1970 From: Petr Mladek Subject: Re: [PATCH 5/5] lib/vsprintf: Add %pfw conversion specifier for printing fwnode names Date: Tue, 26 Mar 2019 16:13:07 +0100 Message-ID: <20190326151307.erqyps6wfvf4on2d@pathway.suse.cz> References: <20190322152930.16642-1-sakari.ailus@linux.intel.com> <20190322152930.16642-6-sakari.ailus@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190322152930.16642-6-sakari.ailus@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Sakari Ailus Cc: linux-kernel@vger.kernel.org, rafael@kernel.org, Andy Shevchenko , linux-acpi@vger.kernel.org, devicetree@vger.kernel.org List-Id: linux-acpi@vger.kernel.org On Fri 2019-03-22 17:29:30, Sakari Ailus wrote: > Add support for %pfw conversion specifier (with "f" and "P" modifiers) to > support printing full path of the node, including its name ("f") and only > the node's name ("P") in the printk family of functions. The two flags > have equivalent functionality to existing %pOF with the same two modifiers > ("f" and "P") on OF based systems. The ability to do the same on ACPI > based systems is added by this patch. > > On ACPI based systems the resulting strings look like > > \_SB.PCI0.CIO2.port@1.endpoint@0 > > where the nodes are separated by a dot (".") and the first three are > ACPI device nodes and the latter two ACPI data nodes. > > Depends-on: ("vsprintf: Remove support for %pF and %pf in favour of %pS and %ps") Reusing obsolete modifiers is dangerous from many reasons: + people might miss the change of the meaning + backporting mistakes + 3rd party modules It might be acceptable if the long term gain is bigger than a short time difficulties. But it would be better to it a safe way when possible. Fortunately, we could keep the backward compatibility for "%pf" and handle only "%pfw*" with the fwnode api. Best Regards, Petr