From patchwork Wed Sep 7 21:58:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Grzeschik X-Patchwork-Id: 603743 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 46766C54EE9 for ; Wed, 7 Sep 2022 21:58:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230039AbiIGV60 (ORCPT ); Wed, 7 Sep 2022 17:58:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59334 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229577AbiIGV6Z (ORCPT ); Wed, 7 Sep 2022 17:58:25 -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 07B4BC3F66 for ; Wed, 7 Sep 2022 14:58:24 -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 1oW33u-0005Gz-Cy; Wed, 07 Sep 2022 23:58:22 +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 1oW33r-004Vmc-JN; Wed, 07 Sep 2022 23:58:21 +0200 Received: from mgr by dude04.red.stw.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1oW33s-00BCd6-Ia; Wed, 07 Sep 2022 23:58:20 +0200 From: Michael Grzeschik To: linux-usb@vger.kernel.org Cc: linux-media@vger.kernel.org, balbi@kernel.org, paul.elder@ideasonboard.com, kieran.bingham@ideasonboard.com, nicolas@ndufresne.ca, laurent.pinchart@ideasonboard.com, kernel@pengutronix.de Subject: [PATCH v4] usb: gadget: uvc: increase worker prio to WQ_HIGHPRI Date: Wed, 7 Sep 2022 23:58:18 +0200 Message-Id: <20220907215818.2670097-1-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 This patch is changing the simple workqueue in the gadget driver to be allocated as async_wq with a higher priority. The pump worker, that is filling the usb requests, will have a higher priority and will not be scheduled away so often while the video stream is handled. This will lead to fewer streaming underruns. Signed-off-by: Michael Grzeschik --- v3 -> v4: - improved commit message to be more clear v2 -> v3: - renamed workqueue to "uvcgadget" v1 -> v2: - added destroy_workqueue in uvc_function_unbind - reworded comment above allow_workqueue drivers/usb/gadget/function/f_uvc.c | 4 ++++ drivers/usb/gadget/function/uvc.h | 1 + drivers/usb/gadget/function/uvc_v4l2.c | 2 +- drivers/usb/gadget/function/uvc_video.c | 9 +++++++-- 4 files changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c index f4f6cf75930beb..09961f4ca981da 100644 --- a/drivers/usb/gadget/function/f_uvc.c +++ b/drivers/usb/gadget/function/f_uvc.c @@ -897,10 +897,14 @@ static void uvc_function_unbind(struct usb_configuration *c, { struct usb_composite_dev *cdev = c->cdev; struct uvc_device *uvc = to_uvc(f); + struct uvc_video *video = &uvc->video; long wait_ret = 1; uvcg_info(f, "%s()\n", __func__); + if (video->async_wq) + destroy_workqueue(video->async_wq); + /* * If we know we're connected via v4l2, then there should be a cleanup * of the device from userspace either via UVC_EVENT_DISCONNECT or diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h index 58e383afdd4406..1a31e6c6a5ffb8 100644 --- a/drivers/usb/gadget/function/uvc.h +++ b/drivers/usb/gadget/function/uvc.h @@ -88,6 +88,7 @@ struct uvc_video { struct usb_ep *ep; struct work_struct pump; + struct workqueue_struct *async_wq; /* Frame parameters */ u8 bpp; diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c index 511f106f984375..d6dbf9b763b2e1 100644 --- a/drivers/usb/gadget/function/uvc_v4l2.c +++ b/drivers/usb/gadget/function/uvc_v4l2.c @@ -170,7 +170,7 @@ uvc_v4l2_qbuf(struct file *file, void *fh, struct v4l2_buffer *b) return ret; if (uvc->state == UVC_STATE_STREAMING) - schedule_work(&video->pump); + queue_work(video->async_wq, &video->pump); return ret; } diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index c00ce0e91f5d5c..bb037fcc90e69e 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -277,7 +277,7 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) spin_unlock_irqrestore(&video->req_lock, flags); if (uvc->state == UVC_STATE_STREAMING) - schedule_work(&video->pump); + queue_work(video->async_wq, &video->pump); } static int @@ -485,7 +485,7 @@ int uvcg_video_enable(struct uvc_video *video, int enable) video->req_int_count = 0; - schedule_work(&video->pump); + queue_work(video->async_wq, &video->pump); return ret; } @@ -499,6 +499,11 @@ int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc) spin_lock_init(&video->req_lock); INIT_WORK(&video->pump, uvcg_video_pump); + /* Allocate a work queue for asynchronous video pump handler. */ + video->async_wq = alloc_workqueue("uvcgadget", WQ_UNBOUND | WQ_HIGHPRI, 0); + if (!video->async_wq) + return -EINVAL; + video->uvc = uvc; video->fcc = V4L2_PIX_FMT_YUYV; video->bpp = 16;