From patchwork Tue Oct 11 20:57:07 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Grzeschik X-Patchwork-Id: 614553 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 8517AC433F5 for ; Tue, 11 Oct 2022 20:57:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229619AbiJKU5N (ORCPT ); Tue, 11 Oct 2022 16:57:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56726 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229542AbiJKU5N (ORCPT ); Tue, 11 Oct 2022 16:57:13 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DC7F804B4 for ; Tue, 11 Oct 2022 13:57:12 -0700 (PDT) Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oiMJK-0005U8-Fp; Tue, 11 Oct 2022 22:57:10 +0200 Received: from [2a0a:edc0:0:1101:1d::ac] (helo=dude04.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtp (Exim 4.94.2) (envelope-from ) id 1oiMJJ-000xeC-Lb; Tue, 11 Oct 2022 22:57:09 +0200 Received: from mgr by dude04.red.stw.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1oiMJI-006j2D-N1; Tue, 11 Oct 2022 22:57:08 +0200 From: Michael Grzeschik To: linux-usb@vger.kernel.org Cc: linux-media@vger.kernel.org, balbi@kernel.org, laurent.pinchart@ideasonboard.com, kernel@pengutronix.de Subject: [PATCH] usb: gadget: uvc: limit isoc_sg to super speed gadgets Date: Tue, 11 Oct 2022 22:57:07 +0200 Message-Id: <20221011205707.1603017-1-m.grzeschik@pengutronix.de> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: mgr@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-usb@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org The overhead of preparing sg data is high for transfers with limited payload. When transferring isoc over high-speed usb the maximum payload is rather small which is a good argument no to use sg. This patch is changing the uvc_video_encode_isoc_sg encode function only to be used for super speed gadgets. Signed-off-by: Michael Grzeschik --- drivers/usb/gadget/function/uvc_video.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index bb037fcc90e69e..5081eb3bc5484c 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -448,6 +448,9 @@ static void uvcg_video_pump(struct work_struct *work) */ int uvcg_video_enable(struct uvc_video *video, int enable) { + struct uvc_device *uvc = video->uvc; + struct usb_composite_dev *cdev = uvc->func.config->cdev; + struct usb_gadget *gadget = cdev->gadget; unsigned int i; int ret; @@ -479,9 +482,11 @@ int uvcg_video_enable(struct uvc_video *video, int enable) if (video->max_payload_size) { video->encode = uvc_video_encode_bulk; video->payload_size = 0; - } else - video->encode = video->queue.use_sg ? + } else { + video->encode = (video->queue.use_sg && + !(gadget->speed <= USB_SPEED_HIGH)) ? uvc_video_encode_isoc_sg : uvc_video_encode_isoc; + } video->req_int_count = 0;