From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E56ADC43334 for ; Mon, 4 Jul 2022 07:24:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231669AbiGDHY3 (ORCPT ); Mon, 4 Jul 2022 03:24:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229656AbiGDHY2 (ORCPT ); Mon, 4 Jul 2022 03:24:28 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D022DB83; Mon, 4 Jul 2022 00:24:27 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 667E060FA6; Mon, 4 Jul 2022 07:24:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41033C3411E; Mon, 4 Jul 2022 07:24:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656919466; bh=WRBaVx9bp/wO2munD1LYq0may6Q0kfaPIzzySbpN3yI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UaW2wnMS/uqOYGlvU3PLCB0EFaXY5J8w/tN4rD/jGxFVkPXiZj2gKu2LjA6MgAjPu 8jaJlqSuhNG1QJc0zysG8JDFKraDO7oUZ/AP0F9G70L3jVVQgwZO9A5+tSNIVpr93m yZOs9jLfcfMeFXPxz2fI6H5lYzp/xa1qVr1I+acc= Date: Mon, 4 Jul 2022 09:24:23 +0200 From: Greg KH To: =?utf-8?Q?=C5=81ukasz?= Spintzyk Cc: netdev@vger.kernel.org, linux-usb@vger.kernel.org, oliver@neukum.org, kuba@kernel.org, ppd-posix@synaptics.com Subject: Re: [PATCH 2/2] net/cdc_ncm: Increase NTB max RX/TX values to 64kb Message-ID: References: <20220704070407.45618-1-lukasz.spintzyk@synaptics.com> <20220704070407.45618-3-lukasz.spintzyk@synaptics.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220704070407.45618-3-lukasz.spintzyk@synaptics.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Jul 04, 2022 at 09:04:07AM +0200, Łukasz Spintzyk wrote: > DisplayLink ethernet devices require NTB buffers larger then 32kb in order to run with highest performance. > > Signed-off-by: Łukasz Spintzyk > --- > include/linux/usb/cdc_ncm.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h > index f7cb3ddce7fb..2d207cb4837d 100644 > --- a/include/linux/usb/cdc_ncm.h > +++ b/include/linux/usb/cdc_ncm.h > @@ -53,8 +53,8 @@ > #define USB_CDC_NCM_NDP32_LENGTH_MIN 0x20 > > /* Maximum NTB length */ > -#define CDC_NCM_NTB_MAX_SIZE_TX 32768 /* bytes */ > -#define CDC_NCM_NTB_MAX_SIZE_RX 32768 /* bytes */ > +#define CDC_NCM_NTB_MAX_SIZE_TX 65536 /* bytes */ > +#define CDC_NCM_NTB_MAX_SIZE_RX 65536 /* bytes */ Does this mess with the throughput of older devices that are not on displaylink connections? What devices did you test this on, and what is the actual performance changes? You offer no real information here at all, and large buffer sizes does have other downsides, so determining how you tested this is key. Also, please wrap your changelogs at 72 columns like git asks you to do. thanks, greg k-h