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 autolearn=unavailable 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 DCAD1C43460 for ; Wed, 28 Apr 2021 23:07:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B0B206113D for ; Wed, 28 Apr 2021 23:07:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231320AbhD1XIJ (ORCPT ); Wed, 28 Apr 2021 19:08:09 -0400 Received: from mout01.posteo.de ([185.67.36.65]:35961 "EHLO mout01.posteo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229488AbhD1XIH (ORCPT ); Wed, 28 Apr 2021 19:08:07 -0400 Received: from submission (posteo.de [89.146.220.130]) by mout01.posteo.de (Postfix) with ESMTPS id B9F18240028 for ; Thu, 29 Apr 2021 01:07:19 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.de; s=2017; t=1619651239; bh=XI1aESVa2Wu/renRfpEbPhHM1YJ/jHSPO7TGIj1lnu0=; h=From:To:Cc:Subject:Date:From; b=rmUL9j6RNfLHOKYRWYtmWRhbobAhbjoLJxIS2MnHCuKQyFLpp3ognoAowXEZchJM/ dvke4CWV5Y5W37dL0TbIFQxoXUvyFh8uxLBAcSFuMZV7hUIAmqQC8lr8lhp8150phN HX9LZol4tHALscuNBilVIQclhkxPeQrxDkEIHjFcljN3SOEkeU9pPdtcuRpvzvCXvd FVk58wHz/Wpq97FAvS5roWDjRFE2vfR0OmFw9NRLRgV4Xv9XKSoA084mPwONsUelnV pk9M3Jge0UOE9L0XIwmBZ5NCnnqGCLr8cnfDnGGEtxkJqCGDxSCRewyD6LxKKoPRj0 SyzVb9BS16sig== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4FVvRB46z2z9rxH; Thu, 29 Apr 2021 01:07:18 +0200 (CEST) From: Benjamin Drung To: Laurent Pinchart , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Adam Goode , Benjamin Drung , stable@vger.kernel.org Subject: [PATCH v2] media: uvcvideo: Fix pixel format change for Elgato Cam Link 4K Date: Wed, 28 Apr 2021 23:03:59 +0000 Message-Id: <20210428230358.22756-1-bdrung@posteo.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The Elgato Cam Link 4K HDMI video capture card reports to support three different pixel formats, where the first format depends on the connected HDMI device. ``` $ v4l2-ctl -d /dev/video0 --list-formats-ext ioctl: VIDIOC_ENUM_FMT Type: Video Capture [0]: 'NV12' (Y/CbCr 4:2:0) Size: Discrete 3840x2160 Interval: Discrete 0.033s (29.970 fps) [1]: 'NV12' (Y/CbCr 4:2:0) Size: Discrete 3840x2160 Interval: Discrete 0.033s (29.970 fps) [2]: 'YU12' (Planar YUV 4:2:0) Size: Discrete 3840x2160 Interval: Discrete 0.033s (29.970 fps) ``` Changing the pixel format to anything besides the first pixel format does not work: ``` v4l2-ctl -d /dev/video0 --try-fmt-video pixelformat=YU12 Format Video Capture: Width/Height : 3840/2160 Pixel Format : 'NV12' (Y/CbCr 4:2:0) Field : None Bytes per Line : 3840 Size Image : 12441600 Colorspace : sRGB Transfer Function : Rec. 709 YCbCr/HSV Encoding: Rec. 709 Quantization : Default (maps to Limited Range) Flags : ``` User space applications like VLC might show an error message on the terminal in that case: ``` libv4l2: error set_fmt gave us a different result than try_fmt! ``` Depending on the error handling of the user space applications, they might display a distorted video, because they use the wrong pixel format for decoding the stream. The Elgato Cam Link 4K responds to the USB video probe VS_PROBE_CONTROL/VS_COMMIT_CONTROL with a malformed data structure: The second byte contains bFormatIndex (instead of being the second byte of bmHint). The first byte is always zero. The third byte is always 1. The firmware bug was reported to Elgato on 2020-12-01 and it was forwarded by the support team to the developers as feature request. There is no firmware update available since then. The latest firmware for Elgato Cam Link 4K as of 2021-03-23 has MCU 20.02.19 and FPGA 67. Therefore add a quirk to correct the malformed data structure. The quirk was successfully tested with VLC, OBS, and Chromium using different pixel formats (YUYV, NV12, YU12), resolutions (3840x2160, 1920x1080), and frame rates (29.970 and 59.940 fps). Cc: stable@vger.kernel.org Signed-off-by: Benjamin Drung --- drivers/media/usb/uvc/uvc_driver.c | 13 +++++++++++++ drivers/media/usb/uvc/uvc_video.c | 21 +++++++++++++++++++++ drivers/media/usb/uvc/uvcvideo.h | 1 + 3 files changed, 35 insertions(+) I am resending this patch since I got no response in the last three weeks. diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c index 9a791d8ef200..6ce58950d78b 100644 --- a/drivers/media/usb/uvc/uvc_driver.c +++ b/drivers/media/usb/uvc/uvc_driver.c @@ -3164,6 +3164,19 @@ static const struct usb_device_id uvc_ids[] = { .bInterfaceSubClass = 1, .bInterfaceProtocol = 0, .driver_info = UVC_INFO_META(V4L2_META_FMT_D4XX) }, + /* + * Elgato Cam Link 4K + * Latest firmware as of 2021-03-23 needs this quirk. + * MCU: 20.02.19, FPGA: 67 + */ + { .match_flags = USB_DEVICE_ID_MATCH_DEVICE + | USB_DEVICE_ID_MATCH_INT_INFO, + .idVendor = 0x0fd9, + .idProduct = 0x0066, + .bInterfaceClass = USB_CLASS_VIDEO, + .bInterfaceSubClass = 1, + .bInterfaceProtocol = 0, + .driver_info = UVC_INFO_QUIRK(UVC_QUIRK_FIX_FORMAT_INDEX) }, /* Generic USB Video Class */ { USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, UVC_PC_PROTOCOL_UNDEFINED) }, { USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, UVC_PC_PROTOCOL_15) }, diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index f2f565281e63..06a538d1008b 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -128,6 +128,27 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, struct uvc_frame *frame = NULL; unsigned int i; + /* + * The response of the Elgato Cam Link 4K is incorrect: The second byte + * contains bFormatIndex (instead of being the second byte of bmHint). + * The first byte is always zero. The third byte is always 1. + * + * The UVC 1.5 class specification defines the first five bits in the + * bmHint bitfield. The remaining bits are reserved and should be zero. + * Therefore a valid bmHint will be less than 32. + */ + if (stream->dev->quirks & UVC_QUIRK_FIX_FORMAT_INDEX && ctrl->bmHint > 255) { + __u8 corrected_format_index; + + corrected_format_index = ctrl->bmHint >> 8; + uvc_dbg(stream->dev, CONTROL, + "Correct USB video probe response from {bmHint: 0x%04x, bFormatIndex: 0x%02x} to {bmHint: 0x%04x, bFormatIndex: 0x%02x}.\n", + ctrl->bmHint, ctrl->bFormatIndex, + ctrl->bFormatIndex, corrected_format_index); + ctrl->bmHint = ctrl->bFormatIndex; + ctrl->bFormatIndex = corrected_format_index; + } + for (i = 0; i < stream->nformats; ++i) { if (stream->format[i].index == ctrl->bFormatIndex) { format = &stream->format[i]; diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h index 97df5ecd66c9..bf401d5ba27d 100644 --- a/drivers/media/usb/uvc/uvcvideo.h +++ b/drivers/media/usb/uvc/uvcvideo.h @@ -209,6 +209,7 @@ #define UVC_QUIRK_RESTORE_CTRLS_ON_INIT 0x00000400 #define UVC_QUIRK_FORCE_Y8 0x00000800 #define UVC_QUIRK_FORCE_BPP 0x00001000 +#define UVC_QUIRK_FIX_FORMAT_INDEX 0x00002000 /* Format flags */ #define UVC_FMT_FLAG_COMPRESSED 0x00000001 -- 2.27.0