From 27c8728510db7bee957ced720990227fa773a14d Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Tue, 4 Oct 2016 15:14:43 +0300 Subject: [PATCH] usb: gadget: function: u_ether: don't starve tx request queue MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 6c83f77278f17a7679001027e9231291c20f0d8a ] 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. Cc: Reported-by: Ville Syrjälä Signed-off-by: Felipe Balbi Signed-off-by: Sasha Levin --- drivers/usb/gadget/function/u_ether.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index 6e6f87656e7b..2e7d27b4cf89 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -591,8 +591,9 @@ 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) % dev->qmult) != 0) : 0;