From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:44928 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1034139AbcKAPCU (ORCPT ); Tue, 1 Nov 2016 11:02:20 -0400 Subject: patch "usb: gadget: u_ether: remove interrupt throttling" added to usb-linus To: felipe.balbi@linux.intel.com, davem@davemloft.net, stable@vger.kernel.org, ville.syrjala@linux.intel.com From: Date: Tue, 01 Nov 2016 09:02:19 -0600 Message-ID: <14780125396111@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled usb: gadget: u_ether: remove interrupt throttling to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >>From fd9afd3cbe404998d732be6cc798f749597c5114 Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Tue, 1 Nov 2016 13:20:22 +0200 Subject: usb: gadget: u_ether: remove interrupt throttling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit According to Dave Miller "the networking stack has a hard requirement that all SKBs which are transmitted must have their completion signalled in a fininte amount of time. This is because, until the SKB is freed by the driver, it holds onto socket, netfilter, and other subsystem resources." In summary, this means that using TX IRQ throttling for the networking gadgets is, at least, complex and we should avoid it for the time being. Cc: Reported-by: Ville Syrjälä Tested-by: Ville Syrjälä Suggested-by: David Miller Signed-off-by: Felipe Balbi --- drivers/usb/gadget/function/u_ether.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index fe1811650dbc..5d1bd13a56c1 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -588,14 +588,6 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, req->length = length; - /* 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)) && - !list_empty(&dev->tx_reqs)) - ? ((atomic_read(&dev->tx_qlen) % dev->qmult) != 0) - : 0; - retval = usb_ep_queue(in, req, GFP_ATOMIC); switch (retval) { default: -- 2.10.2