Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030833AbdDTMNO (ORCPT ); Thu, 20 Apr 2017 08:13:14 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:33767 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S970108AbdDTMNJ (ORCPT ); Thu, 20 Apr 2017 08:13:09 -0400 From: Sjoerd Simons To: linux-serial@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Jiri Slaby Subject: [PATCH v2 2/2] serial: sh-sci: Move uart_register_driver call to device probe Date: Thu, 20 Apr 2017 14:13:01 +0200 Message-Id: <20170420121301.382-3-sjoerd.simons@collabora.co.uk> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170420121301.382-1-sjoerd.simons@collabora.co.uk> References: <20170420121301.382-1-sjoerd.simons@collabora.co.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2248 Lines: 79 uart_register_driver call binds the driver to a specific device node through tty_register_driver call. This should typically happen during device probe call. In a multiplatform scenario, it is possible that multiple serial drivers are part of the kernel. Currently the driver registration fails if multiple serial drivers with overlapping major/minor numbers are included. Signed-off-by: Sjoerd Simons --- Changes in v2: - Add locking to prevent issues when two probes run in parallel drivers/tty/serial/sh-sci.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 9a47cc4f16a2..f23254add9a7 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -2935,6 +2935,7 @@ static inline int sci_probe_earlyprintk(struct platform_device *pdev) static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized"; +static DEFINE_MUTEX(sci_uart_registration_lock); static struct uart_driver sci_uart_driver = { .owner = THIS_MODULE, .driver_name = "sci", @@ -3063,6 +3064,16 @@ static int sci_probe_single(struct platform_device *dev, return -EINVAL; } + mutex_lock(&sci_uart_registration_lock); + if (!sci_uart_driver.state) { + ret = uart_register_driver(&sci_uart_driver); + if (ret) { + mutex_unlock(&sci_uart_registration_lock); + return ret; + } + } + mutex_unlock(&sci_uart_registration_lock); + ret = sci_init_single(dev, sciport, index, p, false); if (ret) return ret; @@ -3186,24 +3197,17 @@ static struct platform_driver sci_driver = { static int __init sci_init(void) { - int ret; - pr_info("%s\n", banner); - ret = uart_register_driver(&sci_uart_driver); - if (likely(ret == 0)) { - ret = platform_driver_register(&sci_driver); - if (unlikely(ret)) - uart_unregister_driver(&sci_uart_driver); - } - - return ret; + return platform_driver_register(&sci_driver); } static void __exit sci_exit(void) { platform_driver_unregister(&sci_driver); - uart_unregister_driver(&sci_uart_driver); + + if (sci_uart_driver.state) + uart_unregister_driver(&sci_uart_driver); } #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE -- 2.11.0