From 8a1509624b4db87773ae17289374b754422895de Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Tue, 1 Nov 2016 13:20:22 +0200 Subject: [PATCH] usb: gadget: u_ether: remove interrupt throttling MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit fd9afd3cbe404998d732be6cc798f749597c5114 upstream. 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. Reported-by: Ville Syrjälä Tested-by: Ville Syrjälä Suggested-by: David Miller Signed-off-by: Felipe Balbi [bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings --- drivers/usb/gadget/u_ether.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/usb/gadget/u_ether.c b/drivers/usb/gadget/u_ether.c index 9a2a1ae9b667..3749269d7954 100644 --- a/drivers/usb/gadget/u_ether.c +++ b/drivers/usb/gadget/u_ether.c @@ -590,13 +590,6 @@ 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) - ? ((atomic_read(&dev->tx_qlen) % qmult) != 0) - : 0; - retval = usb_ep_queue(in, req, GFP_ATOMIC); switch (retval) { default: -- 2.39.2