Patchwork [035/102] USB: serial: add modem-status-change wait queue

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Submitter Luis Henriques
Date April 8, 2013, 9:49 a.m.
Message ID <1365414657-29191-36-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/234649/
State New
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Comments

Luis Henriques - April 8, 2013, 9:49 a.m.
3.5.7.10 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <jhovold@gmail.com>

commit e5b33dc9d16053c2ae4c2c669cf008829530364b upstream.

Add modem-status-change wait queue to struct usb_serial_port that
subdrivers can use to implement TIOCMIWAIT.

Currently subdrivers use a private wait queue which may have been
released when waking up after device disconnected.

Note that we're adding a new wait queue rather than reusing the tty-port
one as we do not want to get woken up at hangup (yet).

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 include/linux/usb/serial.h | 2 ++
 1 file changed, 2 insertions(+)
Johan Hovold - April 8, 2013, 10:01 a.m.
On Mon, Apr 08, 2013 at 10:49:50AM +0100, Luis Henriques wrote:
> 3.5.7.10 -stable review patch.  If anyone has any objections, please let me know.
> 
> ------------------
> 
> From: Johan Hovold <jhovold@gmail.com>
> 
> commit e5b33dc9d16053c2ae4c2c669cf008829530364b upstream.
> 
> Add modem-status-change wait queue to struct usb_serial_port that
> subdrivers can use to implement TIOCMIWAIT.
> 
> Currently subdrivers use a private wait queue which may have been
> released when waking up after device disconnected.
> 
> Note that we're adding a new wait queue rather than reusing the tty-port
> one as we do not want to get woken up at hangup (yet).

This one should be followed by eba0e3c3a0ba7b96f0 (USB: serial: fix hang
when opening port) which adds the missing queue initialisation. It
appears the next patch in your series starts using the wait queue
directly.

Thanks,
Johan

> Signed-off-by: Johan Hovold <jhovold@gmail.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
> ---
>  include/linux/usb/serial.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
> index 86c0b45..0b61f01 100644
> --- a/include/linux/usb/serial.h
> +++ b/include/linux/usb/serial.h
> @@ -66,6 +66,7 @@
>   *	port.
>   * @flags: usb serial port flags
>   * @write_wait: a wait_queue_head_t used by the port.
> + * @delta_msr_wait: modem-status-change wait queue
>   * @work: work queue entry for the line discipline waking up.
>   * @throttled: nonzero if the read urb is inactive to throttle the device
>   * @throttle_req: nonzero if the tty wants to throttle us
> @@ -112,6 +113,7 @@ struct usb_serial_port {
>  
>  	unsigned long		flags;
>  	wait_queue_head_t	write_wait;
> +	wait_queue_head_t	delta_msr_wait;
>  	struct work_struct	work;
>  	char			throttled;
>  	char			throttle_req;
Luis Henriques - April 8, 2013, 10:15 a.m.
On Mon, Apr 08, 2013 at 12:01:57PM +0200, Johan Hovold wrote:
> On Mon, Apr 08, 2013 at 10:49:50AM +0100, Luis Henriques wrote:
> > 3.5.7.10 -stable review patch.  If anyone has any objections, please let me know.
> > 
> > ------------------
> > 
> > From: Johan Hovold <jhovold@gmail.com>
> > 
> > commit e5b33dc9d16053c2ae4c2c669cf008829530364b upstream.
> > 
> > Add modem-status-change wait queue to struct usb_serial_port that
> > subdrivers can use to implement TIOCMIWAIT.
> > 
> > Currently subdrivers use a private wait queue which may have been
> > released when waking up after device disconnected.
> > 
> > Note that we're adding a new wait queue rather than reusing the tty-port
> > one as we do not want to get woken up at hangup (yet).
> 
> This one should be followed by eba0e3c3a0ba7b96f0 (USB: serial: fix hang
> when opening port) which adds the missing queue initialisation. It
> appears the next patch in your series starts using the wait queue
> directly.

Right, I see what you mean.  Not sure how this happen, but obviously the
ordering doesn't make sense.  I'll fix this.  Thanks for your (really
quick!) feedback.

Cheers,
--
Luis


> 
> Thanks, Johan
> 
> > Signed-off-by: Johan Hovold <jhovold@gmail.com>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
> > ---
> >  include/linux/usb/serial.h | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
> > index 86c0b45..0b61f01 100644
> > --- a/include/linux/usb/serial.h
> > +++ b/include/linux/usb/serial.h
> > @@ -66,6 +66,7 @@
> >   *	port.
> >   * @flags: usb serial port flags
> >   * @write_wait: a wait_queue_head_t used by the port.
> > + * @delta_msr_wait: modem-status-change wait queue
> >   * @work: work queue entry for the line discipline waking up.
> >   * @throttled: nonzero if the read urb is inactive to throttle the device
> >   * @throttle_req: nonzero if the tty wants to throttle us
> > @@ -112,6 +113,7 @@ struct usb_serial_port {
> >  
> >  	unsigned long		flags;
> >  	wait_queue_head_t	write_wait;
> > +	wait_queue_head_t	delta_msr_wait;
> >  	struct work_struct	work;
> >  	char			throttled;
> >  	char			throttle_req;

Patch

diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index 86c0b45..0b61f01 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -66,6 +66,7 @@ 
  *	port.
  * @flags: usb serial port flags
  * @write_wait: a wait_queue_head_t used by the port.
+ * @delta_msr_wait: modem-status-change wait queue
  * @work: work queue entry for the line discipline waking up.
  * @throttled: nonzero if the read urb is inactive to throttle the device
  * @throttle_req: nonzero if the tty wants to throttle us
@@ -112,6 +113,7 @@  struct usb_serial_port {
 
 	unsigned long		flags;
 	wait_queue_head_t	write_wait;
+	wait_queue_head_t	delta_msr_wait;
 	struct work_struct	work;
 	char			throttled;
 	char			throttle_req;