e81e7f9a0e
This patch adds support for scatter gather transfers. If the underlying gadgets sg_supported == true, then the videeobuf2-dma-sg is used and the encode routine maps all scatter entries to separate scatterlists for the usb gadget. When streaming 1080p with request size of 1024 times 3 bytes top shows a difference of about 6.4% CPU load applying this patch: PID USER PR NI VIRT RES %CPU %MEM TIME+ S COMMAND 64 root 0 -20 0.0m 0.0m 7.7 0.0 0:01.25 I [kworker/u5:0-uvcvideo] 83 root 0 -20 0.0m 0.0m 4.5 0.0 0:03.71 I [kworker/u5:3-uvcvideo] 307 root -51 0 0.0m 0.0m 3.8 0.0 0:01.05 S [irq/51-dwc3] vs. 64 root 0 -20 0.0m 0.0m 5.8 0.0 0:01.79 I [kworker/u5:0-uvcvideo] 306 root -51 0 0.0m 0.0m 3.2 0.0 0:01.97 S [irq/51-dwc3] 82 root 0 -20 0.0m 0.0m 0.6 0.0 0:01.86 I [kworker/u5:1-uvcvideo] Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de> Link: https://lore.kernel.org/r/20210628155311.16762-5-m.grzeschik@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
24 lines
591 B
C
24 lines
591 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* uvc_video.h -- USB Video Class Gadget driver
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*
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* Copyright (C) 2009-2010
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* Laurent Pinchart (laurent.pinchart@ideasonboard.com)
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*
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* Copyright (c) 2013 Samsung Electronics Co., Ltd.
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* http://www.samsung.com
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* Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
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*/
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#ifndef __UVC_VIDEO_H__
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#define __UVC_VIDEO_H__
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#define UVCG_REQUEST_HEADER_LEN 2
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struct uvc_video;
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int uvcg_video_enable(struct uvc_video *video, int enable);
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int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc);
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#endif /* __UVC_VIDEO_H__ */
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