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 F0B22C47089 for ; Mon, 5 Dec 2022 22:39:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233418AbiLEWjG (ORCPT ); Mon, 5 Dec 2022 17:39:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230235AbiLEWjE (ORCPT ); Mon, 5 Dec 2022 17:39:04 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 55719C31; Mon, 5 Dec 2022 14:39:03 -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 5EFC3589; Mon, 5 Dec 2022 23:39:01 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1670279941; bh=ECF4/ggfsJHS1bBwpAA9kt0ujQT/67nmOpBkwOK9+/8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qslbiqk6nhdSh6yDX0DvE8z1K5c2lqcfWzttSH1qCUHW9ygWc/xxZ3IjXGuopI5VG brJk6kynbGfMwWrkBmv5koTy9MJCdbD2WerqY02sqY00RC1G1yFPb4MKYrfzB2n3dS 14yizv8JOcjjlykuHKpO2z5Z71O93xoeUfAog5LQ= Date: Tue, 6 Dec 2022 00:38:58 +0200 From: Laurent Pinchart To: Ricardo Ribalda Cc: Mauro Carvalho Chehab , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, Yunke Cao , Sergey Senozhatsky Subject: Re: [PATCH v3] media: uvcvideo: Recover stalled ElGato devices Message-ID: References: <20220920-resend-elgato-v3-0-57668054127f@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220920-resend-elgato-v3-0-57668054127f@chromium.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ricardo, Thank you for the patch. On Mon, Dec 05, 2022 at 01:53:01PM +0100, Ricardo Ribalda wrote: > Elgato Cam Link 4k can be in a stalled state if the resolution of > the external source has changed while the firmware initializes. > Once in this state, the device is useless until it receives a > USB reset. It has even been observed that the stalled state will > continue even after unplugging the device. Why, รด, why :'-( > lsusb -v > > Bus 002 Device 002: ID 0fd9:0066 Elgato Systems GmbH Cam Link 4K > Device Descriptor: > bLength 18 > bDescriptorType 1 > bcdUSB 3.00 > bDeviceClass 239 Miscellaneous Device > bDeviceSubClass 2 > bDeviceProtocol 1 Interface Association > bMaxPacketSize0 9 > idVendor 0x0fd9 Elgato Systems GmbH > idProduct 0x0066 > bcdDevice 0.00 > iManufacturer 1 Elgato > iProduct 2 Cam Link 4K > iSerial 4 0005AC52FE000 > bNumConfigurations 1 > > Reviewed-by: Sergey Senozhatsky > Signed-off-by: Ricardo Ribalda > --- > Recover stalled ElGato devices > > Just a resend of this hw fix. > > To: Laurent Pinchart > To: Mauro Carvalho Chehab > Cc: linux-media@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: Sergey Senozhatsky > Cc: Yunke Cao > --- > Changes in v3: > - Add Reviewed-by: Sergey > - Improve identation (Thanks Sergey!) > - Link to v2: https://lore.kernel.org/r/20220920-resend-elgato-v2-0-06b48b3b486a@chromium.org > > Changes in v2: > - Remove info from lsusb > - Link to v1: https://lore.kernel.org/r/20220920-resend-elgato-v1-0-8672a2380e3d@chromium.org > --- > drivers/media/usb/uvc/uvc_video.c | 23 +++++++++++++++++++---- > 1 file changed, 19 insertions(+), 4 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > index 170a008f4006..a8323cf0e9f9 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -129,12 +129,13 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, > return -EPIPE; > } > > +static const struct usb_device_id elgato_cam_link_4k = { > + USB_DEVICE(0x0fd9, 0x0066) > +}; > + > static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, > struct uvc_streaming_control *ctrl) > { > - static const struct usb_device_id elgato_cam_link_4k = { > - USB_DEVICE(0x0fd9, 0x0066) > - }; > struct uvc_format *format = NULL; > struct uvc_frame *frame = NULL; > unsigned int i; > @@ -297,7 +298,7 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream, > dev_err(&stream->intf->dev, > "Failed to query (%u) UVC %s control : %d (exp. %u).\n", > query, probe ? "probe" : "commit", ret, size); > - ret = -EIO; > + ret = (ret == -EPROTO) ? -EPROTO : -EIO; This will change the error returned by VIDIOC_S_FMT and VIDIOC_TRY_FMT, but I don't think that will cause issues. > goto out; > } > > @@ -2121,6 +2122,20 @@ int uvc_video_init(struct uvc_streaming *stream) > * request on the probe control, as required by the UVC specification. > */ > ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR); > + > + /* > + * Elgato Cam Link 4k can be in a stalled state if the resolution of > + * the external source has changed while the firmware initializes. > + * Once in this state, the device is useless until it receives a > + * USB reset. It has even been observed that the stalled state will > + * continue even after unplugging the device. > + */ > + if (usb_match_one_id(stream->dev->intf, &elgato_cam_link_4k) && > + (ret == -EPROTO)) { I'd swap the tests, as the second one is cheaper. You also don't need the inner parentheses. > + usb_reset_device(stream->dev->udev); > + dev_err(&stream->intf->dev, "Restarting Elgato Cam Link 4K\n"); I would also swap those two lines, if an error occurs when resetting the device, it's good to have the "restarting" message printed first. If I understand this correctly, probe will still fail, and the user will have to unplug and replug the device to fix this, right ? If so I'd expand the error message, maybe something along those lines: dev_err(&stream->intf->dev, "Elgato Cam Link 4K firmware crash detected\n"); dev_err(&stream->intf->dev, "Resetting the device, unplug and replug to recover\n"); Reviewed-by: Laurent Pinchart > + } > + > if (ret < 0) > return ret; > > > --- > base-commit: 521a547ced6477c54b4b0cc206000406c221b4d6 > change-id: 20220920-resend-elgato-a845482bdd02 -- Regards, Laurent Pinchart