From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932098AbdBET0e (ORCPT + 2 others); Sun, 5 Feb 2017 14:26:34 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:28245 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752603AbdBET0Z (ORCPT ); Sun, 5 Feb 2017 14:26:25 -0500 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Felipe Balbi , Willy Tarreau Subject: [PATCH 3.10 119/319] usb: gadget: function: u_ether: don't starve tx request queue Date: Sun, 5 Feb 2017 20:19:01 +0100 Message-Id: <1486322541-8206-20-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1486322541-8206-1-git-send-email-w@1wt.eu> References: <1486322541-8206-1-git-send-email-w@1wt.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=latin1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Felipe Balbi commit 6c83f77278f17a7679001027e9231291c20f0d8a upstream. If we don't guarantee that we will always get an interrupt at least when we're queueing our very last request, we could fall into situation where we queue every request with 'no_interrupt' set. This will cause the link to get stuck. The behavior above has been triggered with g_ether and dwc3. Reported-by: Ville Syrjälä Signed-off-by: Felipe Balbi Signed-off-by: Willy Tarreau --- drivers/usb/gadget/u_ether.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/u_ether.c b/drivers/usb/gadget/u_ether.c index 4b76124..aad066d 100644 --- a/drivers/usb/gadget/u_ether.c +++ b/drivers/usb/gadget/u_ether.c @@ -586,8 +586,9 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, /* throttle high/super speed IRQ rate back slightly */ if (gadget_is_dualspeed(dev->gadget)) - req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH || - dev->gadget->speed == USB_SPEED_SUPER) + req->no_interrupt = (((dev->gadget->speed == USB_SPEED_HIGH || + dev->gadget->speed == USB_SPEED_SUPER)) && + !list_empty(&dev->tx_reqs)) ? ((atomic_read(&dev->tx_qlen) % qmult) != 0) : 0; -- 2.8.0.rc2.1.gbe9624a