From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [patch for 2.6.31? 2/2] gigaset: really fix chars_in_buffer Date: Thu, 06 Aug 2009 20:22:27 -0700 (PDT) Message-ID: <20090806.202227.224933454.davem@davemloft.net> References: <200908062219.n76MJXhY024495@imap1.linux-foundation.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, tilman@imap.cc, greg@kroah.com To: akpm@linux-foundation.org Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:57224 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756961AbZHGDWR (ORCPT ); Thu, 6 Aug 2009 23:22:17 -0400 In-Reply-To: <200908062219.n76MJXhY024495@imap1.linux-foundation.org> Sender: netdev-owner@vger.kernel.org List-ID: From: akpm@linux-foundation.org Date: Thu, 06 Aug 2009 15:19:32 -0700 > From: Tilman Schmidt > > The tty_operation chars_in_buffer() is not allowed to return a negative > value to signal an error. Corrects the problem flagged by commit > 23198fda7182969b619613a555f8645fdc3dc334, "tty: fix chars_in_buffers". > > Signed-off-by: Tilman Schmidt > Signed-off-by: Andrew Morton I was letting Alan Cox handle changes in this area since it's TTY stuff, and thus it probably should go to the new TTY mad man, CC:'d :-) > --- > > drivers/isdn/gigaset/interface.c | 19 +++++++------------ > 1 file changed, 7 insertions(+), 12 deletions(-) > > diff -puN drivers/isdn/gigaset/interface.c~gigaset-really-fix-chars_in_buffer drivers/isdn/gigaset/interface.c > --- a/drivers/isdn/gigaset/interface.c~gigaset-really-fix-chars_in_buffer > +++ a/drivers/isdn/gigaset/interface.c > @@ -408,33 +408,28 @@ static int if_write_room(struct tty_stru > return retval; > } > > -/* FIXME: This function does not have error returns */ > - > static int if_chars_in_buffer(struct tty_struct *tty) > { > struct cardstate *cs; > - int retval = -ENODEV; > + int retval = 0; > > cs = (struct cardstate *) tty->driver_data; > if (!cs) { > pr_err("%s: no cardstate\n", __func__); > - return -ENODEV; > + return 0; > } > > gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__); > > - if (mutex_lock_interruptible(&cs->mutex)) > - return -ERESTARTSYS; // FIXME -EINTR? > + mutex_lock(&cs->mutex); > > - if (!cs->connected) { > + if (!cs->connected) > gig_dbg(DEBUG_IF, "not connected"); > - retval = -ENODEV; > - } else if (!cs->open_count) > + else if (!cs->open_count) > dev_warn(cs->dev, "%s: device not opened\n", __func__); > - else if (cs->mstate != MS_LOCKED) { > + else if (cs->mstate != MS_LOCKED) > dev_warn(cs->dev, "can't write to unlocked device\n"); > - retval = -EBUSY; > - } else > + else > retval = cs->ops->chars_in_buffer(cs); > > mutex_unlock(&cs->mutex); > _