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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F079C5479D for ; Sat, 7 Jan 2023 01:21:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232530AbjAGBVE (ORCPT ); Fri, 6 Jan 2023 20:21:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230244AbjAGBU6 (ORCPT ); Fri, 6 Jan 2023 20:20:58 -0500 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 908DC2F7B7; Fri, 6 Jan 2023 17:20:56 -0800 (PST) Received: from pendragon.ideasonboard.com (213-243-189-158.bb.dnainternet.fi [213.243.189.158]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 041404AE; Sat, 7 Jan 2023 02:20:53 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1673054454; bh=oJTSU29ZzZ2zSKpkMZyTLDn7+7RxuAUzsNG2EL1u6BU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=epW3cX+30UotTHzoNr+g/Xe400lZFqUfVkPxVShybDsEk3tt/aQ5yi1MI5soAkcsB 8avyom2S6dim+fDjlpkwRrZVnCp7xQaTXFYt8xduPbLdXUBEy0pgH/49SAyPd56GC8 HZ4oAtXNwI+SuiMkYcoQJYaNsQuxAQoemWOmO3kU= Date: Sat, 7 Jan 2023 03:20:48 +0200 From: Laurent Pinchart To: Ricardo Ribalda Cc: Mauro Carvalho Chehab , linux-kernel@vger.kernel.org, "hn.chen" , linux-media@vger.kernel.org Subject: Re: [PATCH v3 3/8] media: uvc: Create UVC_QUIRK_IGNORE_EMPTY_TS quirk Message-ID: References: <20220920-resend-hwtimestamp-v3-0-db9faee7f47d@chromium.org> <20220920-resend-hwtimestamp-v3-3-db9faee7f47d@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220920-resend-hwtimestamp-v3-3-db9faee7f47d@chromium.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ricardo, Thank you for the patch. On Wed, Jan 04, 2023 at 11:45:21AM +0100, Ricardo Ribalda wrote: > Some SunplusIT cameras took a borderline interpretation of the UVC 1.5 > standard, and fill the PTS and SCR fields with invalid data if the > package does not contain data. > > "STC must be captured when the first video data of a video frame is put > on the USB bus." > > Eg: > > buffer: 0xa7755c00 len 000012 header:0x8c stc 00000000 sof 0000 pts 00000000 > buffer: 0xa7755c00 len 000012 header:0x8c stc 00000000 sof 0000 pts 00000000 > buffer: 0xa7755c00 len 000668 header:0x8c stc 73779dba sof 070c pts 7376d37a > > This borderline/buggy interpretation has been implemented in a variety > of devices, from directly SunplusIT and from other OEMs that rebrand > SunplusIT products. > > Luckily we can identify the affected modules by looking at the guid of > one of the extension units: > > VideoControl Interface Descriptor: > guidExtensionCode {82066163-7050-ab49-b8cc-b3855e8d221d} > > This patch adds a new quirk to take care of this. > > lsusb of one of the affected cameras: > > Bus 001 Device 003: ID 1bcf:2a01 Sunplus Innovation Technology Inc. > Device Descriptor: > bLength 18 > bDescriptorType 1 > bcdUSB 2.01 > bDeviceClass 239 Miscellaneous Device > bDeviceSubClass 2 ? > bDeviceProtocol 1 Interface Association > bMaxPacketSize0 64 > idVendor 0x1bcf Sunplus Innovation Technology Inc. > idProduct 0x2a01 > bcdDevice 0.02 > iManufacturer 1 SunplusIT Inc > iProduct 2 HanChen Wise Camera > iSerial 3 01.00.00 > bNumConfigurations 1 > > Tested-by: HungNien Chen > Signed-off-by: Ricardo Ribalda > --- > drivers/media/usb/uvc/uvc_driver.c | 11 +++++++++++ > drivers/media/usb/uvc/uvc_video.c | 10 ++++++++++ > drivers/media/usb/uvc/uvcvideo.h | 1 + > 3 files changed, 22 insertions(+) > > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c > index 5448576a8413..c5ab6e2d24c3 100644 > --- a/drivers/media/usb/uvc/uvc_driver.c > +++ b/drivers/media/usb/uvc/uvc_driver.c > @@ -1199,6 +1199,17 @@ static const struct uvc_entity_quirk { > u8 guid[16]; > u32 quirks; > } uvc_entity_quirk[] = { > + /* > + * Some SunPlusIT uvc 1.5 device firmware expects that packages with > + * no frame data are ignored by the host. Therefore it does not clear > + * the PTS/SCR bits in the header, and breaks the timestamp decode > + * algorithm. > + */ > + { > + .guid = {0x82, 0x06, 0x61, 0x63, 0x70, 0x50, 0xab, 0x49, > + 0xb8, 0xcc, 0xb3, 0x85, 0x5e, 0x8d, 0x22, 0x1d}, > + .quirks = UVC_QUIRK_IGNORE_EMPTY_TS, > + }, > }; > > static void uvc_entity_quirks(struct uvc_device *dev) > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > index def079c7a6fd..f469c62bedca 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -500,6 +500,16 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf, > if (len < header_size) > return; > > + /* > + * Some devices make a borderline interpreation of the UVC 1.5 standard s/interpreation/interpretation/ > + * and the packets with no data contain undefined timestamps. Ignore "and send packets with no data ..." ? > + * such packages to avoid interfering with the clock interpolation s/packages/packets/ > + * algorithm. > + */ > + if (stream->dev->quirks & UVC_QUIRK_IGNORE_EMPTY_TS && > + len == header_size) > + return; I've sent a reply to v2 which I'll copy here: Given that there may be no guarantee that the above GUID won't be used by devices that don't exhibit this problem, I'm wondering if we couldn't use a heuristics instead of a quirk. I'm thinking about something along the lines of if (buf->bytesused == 0 && len == header_size && has_scr && stc == 0 && sof == 0) This will catch suspicious SCR values (stc == 0 && sof == 0) on empty packets (len == header_size) sent before any data packet (buf->bytesused == 0), which should handle the devices you have to support, and avoid false positives (the stc == 0 && sof == 0 check is already quite restrictive, adding buf->bytesused == 0 would limit the workaround to packets before the first data packet). With this we could drop patch 2/8. > + > /* > * Extract the timestamps: > * > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h > index df93db259312..c3424ae29339 100644 > --- a/drivers/media/usb/uvc/uvcvideo.h > +++ b/drivers/media/usb/uvc/uvcvideo.h > @@ -74,6 +74,7 @@ > #define UVC_QUIRK_RESTORE_CTRLS_ON_INIT 0x00000400 > #define UVC_QUIRK_FORCE_Y8 0x00000800 > #define UVC_QUIRK_FORCE_BPP 0x00001000 > +#define UVC_QUIRK_IGNORE_EMPTY_TS 0x00002000 > > /* Format flags */ > #define UVC_FMT_FLAG_COMPRESSED 0x00000001 -- Regards, Laurent Pinchart