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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83DE2C2B9F4 for ; Mon, 14 Jun 2021 10:40:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 70AB961580 for ; Mon, 14 Jun 2021 10:40:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233055AbhFNKmq (ORCPT ); Mon, 14 Jun 2021 06:42:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233417AbhFNKkj (ORCPT ); Mon, 14 Jun 2021 06:40:39 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F10EC06124A for ; Mon, 14 Jun 2021 03:36:07 -0700 (PDT) Received: from pyrite.rasen.tech (unknown [IPv6:2400:4051:61:600:2c71:1b79:d06d:5032]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id C598F103F; Mon, 14 Jun 2021 12:36:03 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1623666966; bh=x2YQkYljleandnl2PsaPox7SW+V7GCyBb/cB5tioMlE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rfyk6dHy6lXgiRRDA3qSNgn1JUnIzKvOc0kxochh8Vcp8kQOcpxH0c1806NW0dnWF jy+FGBzeexxRDL3m8BxUs3JpHW1pGl78vU8lYe6yTLvMi+QzNucZVzK17uK4UIksLu BbNMzFko0ndXu55jqlixB68uQW7B+AkINAZIKBMY= Date: Mon, 14 Jun 2021 19:35:58 +0900 From: paul.elder@ideasonboard.com To: Michael Grzeschik Cc: linux-usb@vger.kernel.org, laurent.pinchart@ideasonboard.com, caleb.connolly@ideasonboard.com, balbi@kernel.org, kernel@pengutronix.de Subject: Re: [PATCH v2 3/3] usb: gadget: uvc: decrease the interrupt load to a quarter Message-ID: <20210614103558.GB1234605@pyrite.rasen.tech> References: <20210530223041.15320-1-m.grzeschik@pengutronix.de> <20210530223041.15320-4-m.grzeschik@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210530223041.15320-4-m.grzeschik@pengutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Hi Michael, On Mon, May 31, 2021 at 12:30:41AM +0200, Michael Grzeschik wrote: > With usb3 we handle much more requests. It only enables the interrupt on s/much/many/ > every quarter of the allocated requests. This patch decreases the > interrupt load. The last two sentences might be better combined, like: "Decrease the interrupt load by only enabling the interrupt every quarter of the allocated requests." > > Signed-off-by: Michael Grzeschik Other than that, looks good to me. Reviewed-by: Paul Elder > --- > drivers/usb/gadget/function/uvc.h | 2 ++ > drivers/usb/gadget/function/uvc_video.c | 12 ++++++++++++ > 2 files changed, 14 insertions(+) > > diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h > index c1f06d9df5820..5a76e9351b530 100644 > --- a/drivers/usb/gadget/function/uvc.h > +++ b/drivers/usb/gadget/function/uvc.h > @@ -101,6 +101,8 @@ struct uvc_video { > struct list_head req_free; > spinlock_t req_lock; > > + int req_int_count; > + > void (*encode) (struct usb_request *req, struct uvc_video *video, > struct uvc_buffer *buf); > > diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c > index 240d361a45a44..66754687ce217 100644 > --- a/drivers/usb/gadget/function/uvc_video.c > +++ b/drivers/usb/gadget/function/uvc_video.c > @@ -357,6 +357,16 @@ static void uvcg_video_pump(struct work_struct *work) > > video->encode(req, video, buf); > > + if (list_empty(&video->req_free) || > + (buf->state == UVC_BUF_STATE_DONE) || > + (!(video->req_int_count % > + DIV_ROUND_UP(video->uvc_num_requests, 4)))) { > + video->req_int_count = 0; > + req->no_interrupt = 0; > + } else { > + req->no_interrupt = 1; > + } > + > /* Queue the USB request */ > ret = uvcg_video_ep_queue(video, req); > spin_unlock_irqrestore(&queue->irqlock, flags); > @@ -365,6 +375,7 @@ static void uvcg_video_pump(struct work_struct *work) > uvcg_queue_cancel(queue, 0); > break; > } > + video->req_int_count++; > } > > spin_lock_irqsave(&video->req_lock, flags); > @@ -437,6 +448,7 @@ int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc) > video->width = 320; > video->height = 240; > video->imagesize = 320 * 240 * 2; > + video->req_int_count = 0; > > /* Initialize the video buffers queue. */ > uvcg_queue_init(uvc->v4l2_dev.dev, &video->queue, V4L2_BUF_TYPE_VIDEO_OUTPUT, > -- > 2.29.2 >