From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754625AbdCTMkH (ORCPT ); Mon, 20 Mar 2017 08:40:07 -0400 Received: from fllnx209.ext.ti.com ([198.47.19.16]:60608 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753766AbdCTMkF (ORCPT ); Mon, 20 Mar 2017 08:40:05 -0400 Subject: Re: [PATCH] serial: 8250: 8250_core: Fix irq name for 8250 serial irq To: Andy Shevchenko , Russell King - ARM Linux References: <20170316122653.19930-1-vigneshr@ti.com> <20170316133632.GV21222@n2100.armlinux.org.uk> <9a6dcf55-0ace-e617-73bc-0472a939b36c@arm.com> CC: Robin Murphy , Jisheng Zhang , Greg Kroah-Hartman , "linux-kernel@vger.kernel.org" , "linux-serial@vger.kernel.org" , Jiri Slaby , linux-arm Mailing List From: Vignesh R Message-ID: <55b5a9d2-9416-3a3d-24ab-e819dae5f3fc@ti.com> Date: Mon, 20 Mar 2017 17:54:57 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 17 March 2017 02:28 AM, Andy Shevchenko wrote: > On Thu, Mar 16, 2017 at 4:55 PM, Robin Murphy wrote: >> On 16/03/17 13:36, Russell King - ARM Linux wrote: >>> On Thu, Mar 16, 2017 at 05:56:53PM +0530, Vignesh R wrote: >>>> Using dev_name() as irq name during request_irq() might be misleading in >>>> case of serial over PCI. Therefore use a better alternative name for >>>> identifying serial port irqs as "serial" appended with serial_index of >>>> the port. This ensures that "serial" string is always present in irq >>>> name while port index will help in distinguishing b/w different ports. >>> >>> Wouldn't it be better to use the device name (iow, ttySx) rather than >>> "serialx" ? >>> >>> Maybe a helper function in serial_core.c to format the device name into >>> a supplied string, which can be re-used elsewhere, eg, uart_report_port() >>> and uart_suspend_port(). IOW: >>> >>> const char *uart_port_name(char *buf, size_t n, struct uart_driver *drv, >>> struct uart_port *port) >>> { >>> snprintf(buf, n, "%s%d", drv->dev_name, >>> drv->tty_driver->name_base + port->line); >>> >>> return buf; >>> } >>> >>> which means you can do this: >>> >>> char name[16]; >>> >>> request_irq(..., uart_port_name(name, sizeof(name), driver, port), ...) >>> >>> which also avoids the allocation. >> >> ...and makes 'cat /proc/interrupts' particularly fun later: >> >> 8: 0 GICv2 72 Level � �h ����V! >> >> Unless a suitably long-lived string already exists somewhere else in the >> serial core, the allocation is unavoidable, although kasprintf() (or its >> devm_ variant) might make matters a little simpler. > > What prevents us to create a field in uart_port (uart8250_port?) where > we put the uart_port_name() for future use as long as uart_port is > alive? > Thanks for the suggestions. I will explore adding a field to uart_port struct and provide a corresponding helper function uart_port_name() and come up with a patch. -- Regards Vignesh