From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752155Ab2H0Ney (ORCPT ); Mon, 27 Aug 2012 09:34:54 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:42680 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751082Ab2H0Nex (ORCPT ); Mon, 27 Aug 2012 09:34:53 -0400 From: Baodong Chen To: gregkh@linuxfoundation.org, jslaby@suse.cz, davem@davemloft.net Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Baodong Chen Subject: [PATCH] staging:fixed code to fit tty_driver's kref filed fixed code to fit tty_driver's kref filed for drivers/staging/net/pc300_tty.c Date: Mon, 27 Aug 2012 21:34:18 +0800 Message-Id: <1346074458-2659-1-git-send-email-chenbdchenbd@gmail.com> X-Mailer: git-send-email 1.7.0.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Signed-off-by: Baodong Chen --- drivers/staging/net/pc300_tty.c | 55 ++++++++++++++++++++++----------------- 1 files changed, 31 insertions(+), 24 deletions(-) diff --git a/drivers/staging/net/pc300_tty.c b/drivers/staging/net/pc300_tty.c index 4709f42..91ada93 100644 --- a/drivers/staging/net/pc300_tty.c +++ b/drivers/staging/net/pc300_tty.c @@ -46,6 +46,8 @@ #include #include #include +#include + /* TTY includes */ #include #include @@ -134,12 +136,26 @@ static void cpc_tty_signal_on(pc300dev_t *pc300dev, unsigned char); static int pc300_tiocmset(struct tty_struct *, unsigned int, unsigned int); static int pc300_tiocmget(struct tty_struct *); +static void cpc_tty_do_unreg_driver(struct kref *ref); + /* functions called by PC300 driver */ void cpc_tty_init(pc300dev_t *dev); void cpc_tty_unregister_service(pc300dev_t *pc300dev); void cpc_tty_receive(pc300dev_t *pc300dev); void cpc_tty_trigger_poll(pc300dev_t *pc300dev); +static void cpc_tty_do_unreg_driver(struct kref *ref) +{ + struct tty_driver *drv = container_of(ref, struct tty_driver, kref); + int ret; + + cpc_tty_unreg_flag = 0; + + res = tty_unregister_driver(drv); + if (res) + CPC_TTY_DBG("unregister the tty driver error=%d\n", res); +} + /* * PC300 TTY clear "signal" */ @@ -239,6 +255,8 @@ void cpc_tty_init(pc300dev_t *pc300dev) /* interface routines from the upper tty layer to the tty driver */ tty_set_operations(&serial_drv, &pc300_ops); + kref_init(&serial_drv.kref); + /* register the TTY driver */ if (tty_register_driver(&serial_drv)) { printk("%s-tty: Failed to register serial driver! ", @@ -408,13 +426,9 @@ static void cpc_tty_close(struct tty_struct *tty, struct file *flip) CPC_TTY_DBG("%s: TTY closed\n",cpc_tty->name); - if (!serial_drv.refcount && cpc_tty_unreg_flag) { - cpc_tty_unreg_flag = 0; - CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name); - if ((res=tty_unregister_driver(&serial_drv))) { - CPC_TTY_DBG("%s: ERROR ->unregister the tty driver error=%d\n", - cpc_tty->name,res); - } + if (cpc_tty_unreg_flag) { + CPC_TTY_DBG("%s: checking unregister the tty driver...\n", cpc_tty->name); + kref_put(&serial_drv.kref, cpc_tty_do_unreg_driver); } return; } @@ -644,13 +658,9 @@ static void cpc_tty_hangup(struct tty_struct *tty) CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name); return ; } - if (!serial_drv.refcount && cpc_tty_unreg_flag) { - cpc_tty_unreg_flag = 0; - CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name); - if ((res=tty_unregister_driver(&serial_drv))) { - CPC_TTY_DBG("%s: ERROR ->unregister the tty driver error=%d\n", - cpc_tty->name,res); - } + if (cpc_tty_unreg_flag) { + CPC_TTY_DBG("%s: checking unregister the tty driver...\n", cpc_tty->name); + kref_put(&serial_drv.kref, cpc_tty_do_unreg_driver); } cpc_tty_signal_off(cpc_tty->pc300dev, CTL_DTR); } @@ -1043,19 +1053,16 @@ void cpc_tty_unregister_service(pc300dev_t *pc300dev) return; } - if (--cpc_tty_cnt == 0) { - if (serial_drv.refcount) { - CPC_TTY_DBG("%s: unregister is not possible, refcount=%d", - cpc_tty->name, serial_drv.refcount); + if (--cpc_tty_cnt == 0) { + CPC_TTY_DBG("%s: checking unregister the tty driver...\n", + cpc_tty->name); + res = kref_put(&serial_drv.kref, cpc_tty_do_unreg_driver); + if (0 == res) { + CPC_TTY_DBG("%s: unregister is not possible\n", + cpc_tty->name); cpc_tty_cnt++; cpc_tty_unreg_flag = 1; return; - } else { - CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name); - if ((res=tty_unregister_driver(&serial_drv))) { - CPC_TTY_DBG("%s: ERROR ->unregister the tty driver error=%d\n", - cpc_tty->name,res); - } } } CPC_TTY_LOCK(pc300dev->chan->card,flags); -- 1.7.0.4