From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: NAPI on USB network drivers Date: Wed, 25 Jan 2017 14:32:26 -0500 (EST) Message-ID: <20170125.143226.525018584694503090.davem@davemloft.net> References: <1485336881.16604.2.camel@suse.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: hayeswang@realtek.com, netdev@vger.kernel.org, linux-usb@vger.kernel.org To: oneukum@suse.com Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:32838 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750768AbdAYTc2 (ORCPT ); Wed, 25 Jan 2017 14:32:28 -0500 In-Reply-To: <1485336881.16604.2.camel@suse.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Oliver Neukum Date: Wed, 25 Jan 2017 10:34:41 +0100 > looking at r8152 I noticed that it uses NAPI. I never considered > this for the generic USB networking code as you cannot disable > interrupts for USB. Is it still worth it? What are the benefits? I think it's not a good approach for getting GRO. Exactly because of the issue you raise, in that USB drivers cannot stop the URBs from coming in while running their poll method.