3.16.40-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Felipe Balbi <[email protected]> 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 <[email protected]> Tested-by: Ville Syrjälä <[email protected]> Suggested-by: David Miller <[email protected]> Signed-off-by: Felipe Balbi <[email protected]> [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings <[email protected]> --- --- a/drivers/usb/gadget/u_ether.c +++ b/drivers/usb/gadget/u_ether.c @@ -583,13 +583,6 @@ static netdev_tx_t eth_start_xmit(struct 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) % dev->qmult) != 0) - : 0; - retval = usb_ep_queue(in, req, GFP_ATOMIC); switch (retval) { default:
