From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753078Ab0ASNTv (ORCPT ); Tue, 19 Jan 2010 08:19:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752163Ab0ASNTu (ORCPT ); Tue, 19 Jan 2010 08:19:50 -0500 Received: from smtp-out002.kontent.com ([81.88.40.216]:33541 "EHLO smtp-out002.kontent.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751590Ab0ASNTt (ORCPT ); Tue, 19 Jan 2010 08:19:49 -0500 From: Oliver Neukum To: Matthew Garrett Subject: Re: [REGRESSION] "USB: use kfifo to buffer usb-generic serial writes" causes gobi_loader to hang Date: Tue, 19 Jan 2010 14:20:29 +0100 User-Agent: KMail/1.12.2 (Linux/2.6.33-rc3-0.1-default; KDE/4.3.1; x86_64; ; ) Cc: dvomlehn@cisco.com, gregkh@suse.de, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org References: <20100117025535.GB7045@srcf.ucam.org> <201001181825.39823.oliver@neukum.org> <20100118201416.GA26511@srcf.ucam.org> In-Reply-To: <20100118201416.GA26511@srcf.ucam.org> MIME-Version: 1.0 Content-Type: Multipart/Mixed; boundary="Boundary-00=_dGbVLPFLLlx2qRL" Message-Id: <201001191420.29652.oliver@neukum.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Boundary-00=_dGbVLPFLLlx2qRL Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Am Montag, 18. Januar 2010 21:14:16 schrieb Matthew Garrett: > drivers/usb/serial/generic.c: usb_serial_generic_write - port 0, 1565 > bytes > drivers/usb/serial/generic.c: usb_serial_generic_write - put 0 bytes > into fifo > drivers/usb/serial/generic.c: usb_serial_generic_read_bulk_callback - > port 0 If the FIFO is full we can do nothing. Please try the attached patch. Regards Oliver --Boundary-00=_dGbVLPFLLlx2qRL Content-Type: text/x-patch; charset="UTF-8"; name="0001-usb-serial-Deal-with-filled-FIFO.patch" Content-Transfer-Encoding: quoted-printable Content-Disposition: attachment; filename="0001-usb-serial-Deal-with-filled-FIFO.patch" =46rom d7317bae0772b794a1cc9b832bc3d3e1b3642a13 Mon Sep 17 00:00:00 2001 =46rom: Oliver Neukum Date: Tue, 19 Jan 2010 14:16:41 +0100 Subject: [PATCH] usb:serial:Deal with filled FIFO Bail out if the FIFO is filled Signed-off-by: Oliver Neukum =2D-- drivers/usb/serial/generic.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c index 76e5514..053f7f1 100644 =2D-- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -349,6 +349,10 @@ int usb_serial_generic_write(struct tty_struct *tty, =20 count =3D kfifo_in_locked(&port->write_fifo, buf, count, &port->lock); dbg("%s - put %d bytes into fifo", __func__, count); + if (!count) { + dbg("%s - FIFO is full", __func__); + return 0; + } result =3D usb_serial_generic_write_start(port); =20 if (result >=3D 0) =2D-=20 1.6.4.2 --Boundary-00=_dGbVLPFLLlx2qRL--