From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752249AbbCYQUg (ORCPT ); Wed, 25 Mar 2015 12:20:36 -0400 Received: from mail-qg0-f41.google.com ([209.85.192.41]:35464 "EHLO mail-qg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751736AbbCYQUd (ORCPT ); Wed, 25 Mar 2015 12:20:33 -0400 Message-ID: <5512E044.4080700@hurleysoftware.com> Date: Wed, 25 Mar 2015 12:20:20 -0400 From: Peter Hurley User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: NeilBrown CC: Mark Rutland , One Thousand Gnomes , Arnd Bergmann , Greg Kroah-Hartman , Sebastian Reichel , Pavel Machek , Grant Likely , Jiri Slaby , GTA04 owners , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] TTY: use class_find_device to find port in uart_suspend/resume. References: <20150318055437.21025.13990.stgit@notabene.brown> <20150318055831.21025.27864.stgit@notabene.brown> In-Reply-To: <20150318055831.21025.27864.stgit@notabene.brown> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Neil, On 03/18/2015 01:58 AM, NeilBrown wrote: > uart_{suspend,resume}_port seach the children of a uart device > to find a particular tty device. > This requires all the ttys to be direct children of the uart. > > A future patch will allow a 'tty_slave' to intervene between > the port and the uart, voiding this requirement. > > So change to use class_find_device. This is made possibly by > exporting a "tty_find_device" from tty_io.c Comments below. > Signed-off-by: NeilBrown > --- > drivers/tty/serial/serial_core.c | 21 ++++++++------------- > drivers/tty/tty_io.c | 6 ++++++ > include/linux/tty.h | 1 + > 3 files changed, 15 insertions(+), 13 deletions(-) > > diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c > index 6a1055ae3437..7abb7474870a 100644 > --- a/drivers/tty/serial/serial_core.c > +++ b/drivers/tty/serial/serial_core.c > @@ -1960,26 +1960,19 @@ struct uart_match { > struct uart_driver *driver; > }; > > -static int serial_match_port(struct device *dev, void *data) > -{ > - struct uart_match *match = data; > - struct tty_driver *tty_drv = match->driver->tty_driver; > - dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) + > - match->port->line; > - > - return dev->devt == devt; /* Actually, only one tty per port */ > -} > > int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) > { > struct uart_state *state = drv->state + uport->line; > struct tty_port *port = &state->port; > struct device *tty_dev; > - struct uart_match match = {uport, drv}; > + dev_t devt = MKDEV(drv->tty_driver->major, > + drv->tty_driver->minor_start) + > + uport->line; > > mutex_lock(&port->mutex); > > - tty_dev = device_find_child(uport->dev, &match, serial_match_port); > + tty_dev = tty_find_device(devt); > if (device_may_wakeup(tty_dev)) { > if (!enable_irq_wake(uport->irq)) > uport->irq_wake = 1; > @@ -2039,12 +2032,14 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) > struct uart_state *state = drv->state + uport->line; > struct tty_port *port = &state->port; > struct device *tty_dev; > - struct uart_match match = {uport, drv}; > struct ktermios termios; > + dev_t devt = MKDEV(drv->tty_driver->major, > + drv->tty_driver->minor_start) + > + uport->line; > > mutex_lock(&port->mutex); > > - tty_dev = device_find_child(uport->dev, &match, serial_match_port); > + tty_dev = tty_find_device(devt); > if (!uport->suspended && device_may_wakeup(tty_dev)) { > if (uport->irq_wake) { > disable_irq_wake(uport->irq); > diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c > index 51f066aa375e..27632ad17d6f 100644 > --- a/drivers/tty/tty_io.c > +++ b/drivers/tty/tty_io.c > @@ -3077,6 +3077,12 @@ static struct device *tty_get_device(struct tty_struct *tty) > return class_find_device(tty_class, NULL, &devt, dev_match_devt); > } > > +struct device *tty_find_device(dev_t devt) > +{ > + return class_find_device(tty_class, NULL, &devt, dev_match_devt); > +} > +EXPORT_SYMBOL(tty_find_device); > + Would you please replace tty_get_device() usage with tty_find_device() (and keep the function comment from tty_get_device())? Regards, Peter Hurley > > /** > * alloc_tty_struct > diff --git a/include/linux/tty.h b/include/linux/tty.h > index 358a337af598..04d5f1213700 100644 > --- a/include/linux/tty.h > +++ b/include/linux/tty.h > @@ -461,6 +461,7 @@ extern void tty_vhangup(struct tty_struct *tty); > extern int tty_hung_up_p(struct file *filp); > extern void do_SAK(struct tty_struct *tty); > extern void __do_SAK(struct tty_struct *tty); > +extern struct device *tty_find_device(dev_t devt); > extern void no_tty(void); > extern void tty_flush_to_ldisc(struct tty_struct *tty); > extern void tty_buffer_free_all(struct tty_port *port); > >