From patchwork Sun Feb 12 17:56:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krishna Kurapati X-Patchwork-Id: 653095 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 4F9F3C05027 for ; Sun, 12 Feb 2023 17:57:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229614AbjBLR5W (ORCPT ); Sun, 12 Feb 2023 12:57:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44800 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229514AbjBLR5V (ORCPT ); Sun, 12 Feb 2023 12:57:21 -0500 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A30FCBDDE; Sun, 12 Feb 2023 09:57:20 -0800 (PST) Received: from pps.filterd (m0279872.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 31CHvI92026860; Sun, 12 Feb 2023 17:57:18 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=qcppdkim1; bh=u4CrzYM17ps5RxQQZYz8Hzad/nALC78BEWVZhD6asao=; b=px9LvwXR9NATtFV0ngMLPLSeFtXtKYiKk9B3ZA5WwGFD+XHtSfF9uSDdUcMQrL6o0Q0T qRCQNeNbCWrwCznKbbxlqMttad5ax6TMcxexxlBiocRZVD7kGILsFnhoLYsFuXExxe0a zpo9wFhENQfpVVx8ladUizzJggbfLgHd0zTaR/LWcM2eIT6x8ykNyGdXnse0LFEZO3ek sFa7AlIRdG12ZHZ/aY1aLNrElr3koKlWTZMxXHMpXjJW3py4ou1QOfRlTT6wcSD1Ey5D KTtauOeePnLoO/7vuarD459RdjtwEXRD5SBgTlCuLrtoyo/5zxt8dxznBKmENzUJtuf8 Eg== Received: from nalasppmta02.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3np3detd88-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 12 Feb 2023 17:57:17 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA02.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 31CHvGbC003885 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 12 Feb 2023 17:57:16 GMT Received: from hu-kriskura-hyd.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Sun, 12 Feb 2023 09:57:14 -0800 From: Krishna Kurapati To: Greg Kroah-Hartman , =?utf-8?q?Maciej_=C5=BB?= =?utf-8?q?enczykowski?= CC: , , , , Krishna Kurapati Subject: [RFC] usb: gadget: ncm: Add support to configure wMaSegmentSize Date: Sun, 12 Feb 2023 23:26:59 +0530 Message-ID: <20230212175659.4480-1-quic_kriskura@quicinc.com> X-Mailer: git-send-email 2.39.0 MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: 5PLi-V00T40iaUWVtlMvy76AL5ZE5Ge6 X-Proofpoint-ORIG-GUID: 5PLi-V00T40iaUWVtlMvy76AL5ZE5Ge6 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.170.22 definitions=2023-02-12_06,2023-02-09_03,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 mlxscore=0 clxscore=1011 adultscore=0 mlxlogscore=999 malwarescore=0 phishscore=0 lowpriorityscore=0 bulkscore=0 priorityscore=1501 impostorscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2302120162 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Currently the NCM driver restricts wMasxSegmentSize that indicates the datagram size coming from network layer to 1514. However the spec doesn't have any limitation. Add support to configure this value before configfs symlink is created. Also since the NTB Out/In buffer sizes are fixed at 16384 bytes, limit the segment size to an upper cap of 8192 bytes so that at least 2 packets can be aggregated. Signed-off-by: Krishna Kurapati --- drivers/usb/gadget/function/f_ncm.c | 55 +++++++++++++++++++++++++++++ drivers/usb/gadget/function/u_ncm.h | 1 + 2 files changed, 56 insertions(+) diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c index 424bb3b666db..1969e276017f 100644 --- a/drivers/usb/gadget/function/f_ncm.c +++ b/drivers/usb/gadget/function/f_ncm.c @@ -118,6 +118,12 @@ static inline unsigned ncm_bitrate(struct usb_gadget *g) /* Delay for the transmit to wait before sending an unfilled NTB frame. */ #define TX_TIMEOUT_NSECS 300000 +/* + * Currently the max NTB Buffer size is set to 16384. For atleast 2 packets + * to be aggregated, the size of datagram must at max be 8192. + */ +#define MAX_DATAGRAM_SIZE 8192 + #define FORMATS_SUPPORTED (USB_CDC_NCM_NTB16_SUPPORTED | \ USB_CDC_NCM_NTB32_SUPPORTED) @@ -1440,6 +1446,7 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) */ if (!ncm_opts->bound) { mutex_lock(&ncm_opts->lock); + ncm_opts->net->mtu = (ncm_opts->max_segment_size - 14); gether_set_gadget(ncm_opts->net, cdev->gadget); status = gether_register_netdev(ncm_opts->net); mutex_unlock(&ncm_opts->lock); @@ -1484,6 +1491,8 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) status = -ENODEV; + ecm_desc.wMaxSegmentSize = ncm_opts->max_segment_size; + /* allocate instance-specific endpoints */ ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_in_desc); if (!ep) @@ -1586,11 +1595,56 @@ USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ncm); /* f_ncm_opts_ifname */ USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ncm); +static ssize_t ncm_opts_max_segment_size_show(struct config_item *item, + char *page) +{ + struct f_ncm_opts *opts = to_f_ncm_opts(item); + u32 segment_size; + + mutex_lock(&opts->lock); + segment_size = opts->max_segment_size; + mutex_unlock(&opts->lock); + + return sprintf(page, "%u\n", segment_size); +} + +static ssize_t ncm_opts_max_segment_size_store(struct config_item *item, + const char *page, size_t len) +{ + struct f_ncm_opts *opts = to_f_ncm_opts(item); + int ret; + u32 segment_size; + + mutex_lock(&opts->lock); + if (opts->refcnt) { + ret = -EBUSY; + goto out; + } + + ret = kstrtou32(page, 0, &segment_size); + if (ret) + goto out; + + if (segment_size > MAX_DATAGRAM_SIZE) { + ret = -EINVAL; + goto out; + } + + opts->max_segment_size = segment_size; + ret = len; +out: + mutex_unlock(&opts->lock); + return ret; +} + +CONFIGFS_ATTR(ncm_opts_, max_segment_size); + static struct configfs_attribute *ncm_attrs[] = { &ncm_opts_attr_dev_addr, &ncm_opts_attr_host_addr, &ncm_opts_attr_qmult, &ncm_opts_attr_ifname, + &ncm_opts_attr_max_segment_size, NULL, }; @@ -1633,6 +1687,7 @@ static struct usb_function_instance *ncm_alloc_inst(void) kfree(opts); return ERR_CAST(net); } + opts->max_segment_size = cpu_to_le16(ETH_FRAME_LEN); INIT_LIST_HEAD(&opts->ncm_os_desc.ext_prop); descs[0] = &opts->ncm_os_desc; diff --git a/drivers/usb/gadget/function/u_ncm.h b/drivers/usb/gadget/function/u_ncm.h index 5408854d8407..fab99d997476 100644 --- a/drivers/usb/gadget/function/u_ncm.h +++ b/drivers/usb/gadget/function/u_ncm.h @@ -31,6 +31,7 @@ struct f_ncm_opts { */ struct mutex lock; int refcnt; + u32 max_segment_size; }; #endif /* U_NCM_H */