From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Cernekee Subject: Re: [PATCH 2/2] tty: serial: bcm63xx: Allow device nodes to be renamed to /dev/ttyBCM* Date: Mon, 10 Nov 2014 11:50:56 -0800 Message-ID: References: <1415523348-4631-1-git-send-email-cernekee@gmail.com> <1415523348-4631-2-git-send-email-cernekee@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: Sender: stable-owner@vger.kernel.org To: Rob Herring Cc: Greg Kroah-Hartman , Jiri Slaby , Grant Likely , Florian Fainelli , Maxime Bizon , Jonas Gorski , Linux-MIPS , "linux-serial@vger.kernel.org" , "devicetree@vger.kernel.org" , stable@vger.kernel.org List-Id: devicetree@vger.kernel.org On Mon, Nov 10, 2014 at 11:22 AM, Rob Herring wrote: >>> This can be solved with a udev rule to create sym links. >> >> Is it safe to register two console drivers named "ttyS" with the same >> major/minor numbers? Maybe there is a trick to making them coexist? > > No, but I think you can do dynamic minor numbers. I seem to recall > this coming up with the Samsung UARTs a while back. The other variations I've seen in the tree are: nwpserial: ttySQ, major 4 minor 68 (not 64) sunhv, sunsab, sunsu, sunzilog: set uart_driver->major to 4 but let uart_driver->minor default to 0 SERIAL_ATMEL_TTYAT: compile-time selectable between ttySn (4/64) and ttyATn (204/154). txx9 does something similar using SERIAL_TXX9_STDSERIAL. A whole bunch of other SoC serial drivers use major 204 and a custom name like "ttyAL". Some of these show up in Documentation/devices.txt; others don't. ~3 drivers use 204/64 from the middle of the Altix assigned range. What is the current best practice for new drivers?