From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f53.google.com (mail-ej1-f53.google.com [209.85.218.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7F1217D098 for ; Sun, 7 Dec 2025 00:37:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765067862; cv=none; b=nyvvjGLwh3TsDEhcE8nlP56RliIFk2YVtdZ9yG8Jg0snT1rSe//2QDMw4Ki2BFxKSGs4ujL/yrCcIvh59FbeyP9HQoaSPGldiPZjysnZ5fRvmi1p7GwUEDDaU1kl0QXuj1bHjYtIzFbow5VZPR1ZioM0J5QJPPtnbQtNhoBl5cg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765067862; c=relaxed/simple; bh=oMBXKBpzKMyRpLgpUr0w2CwPWmutktGRt5cXvS+uaBM=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=NQe7aXOpmxvqlwcn+d+yiCoOR16dxHjyr/OtsIwKRkH8Q9/u45RQS/wfBFKGfWEIS8HwYz+Wg56oL+CLJHFp3VxKg925pFjPSW1IHPr+xYk/CxDqf8b+dM/UQYiKtqMecgbbuc78iIb5AeqBRlivSY4Wec5adDWyIUAC3m8XYN0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=UPgqIQ2F; arc=none smtp.client-ip=209.85.218.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UPgqIQ2F" Received: by mail-ej1-f53.google.com with SMTP id a640c23a62f3a-b735ce67d1dso537249366b.3 for ; Sat, 06 Dec 2025 16:37:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1765067859; x=1765672659; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=3vM01g150+QWducT+gASJyqHE2lTKdYg0871uytSpEY=; b=UPgqIQ2F5XH2llSgMyXPGt8SyHVU2wJse+2J3qG+2HaLyrYPZ3MSiLAxmi/iC1s3VE AXun0w1YrWEQJ4CPWEx8BMxXDe9XMfUbkkJcDgdAQz2cpl9L9QXRq3LlAQSHnueYuf2V lE+Dc0r+k40LhjtYgnUofJIadM1yQalGNKyJa7bw8iQhHuoRM2ZxIFS6xOam2doZQhTM OuaFK1Mj+SIRGOqoWQ/E5bf3J3YPPo1JXe5aYYK7NF1aGxX73zhFyXbvz+PdT0WhnlmW GSKs55GmMwBSyR9hTjXMo8OzACkG6FB2yao3J5CUYVJV3N4Ws53qB/OwM5ERou5Nj2iE 76zg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1765067859; x=1765672659; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=3vM01g150+QWducT+gASJyqHE2lTKdYg0871uytSpEY=; b=iiv+TdCKtmjdt4EEEWEJ/BWptvqlHNucFDyThqyDHUbi7dBm7ACaIBBL+i1snOy1J9 GSSuhXodhPR+skzWSBKTAsxYEeDBKRSfsVEOSRCEYQVpJeQx/HUiRxeQerge7aSWoJ8h ACZHeqjNXvUwMq/etfozjViqaz8BSrK78lKzZWRQCKYBQuX5QHO1slesPceiTcv1Xqeo ldZMXgIVyQq/SM79UlIj0RAgoGWxqyVuRi9sMjj4z/0Fh+cPWToFp+quC+VIsVWkfpXn XfgHr9JP43mYyfAk0FZoxWvMAA8oUQSL3bJBEf8SRDqi+n/JubxtxO8Trnp+oUDdc/ah qZXw== X-Gm-Message-State: AOJu0Yz4UD7Sy4jPtF/hMsuRDrzOp2Ue150B0yztPBJt+CI3zj+y0UQd PZGXT7bU/UZykf/TP0wk62vZjQ7CF60TcTNUf9w7jxDM69gBrM1/DJTQw088qg== X-Gm-Gg: ASbGncu70Jn7FfAN5LyTunIxbPhQXYRZLhCEaHJKkygFTO4dgJPQDy20jiQi5zOJmo6 3mkjp7esuE0jhoTQtDW1+MlKJqg9zdWnqzm/XQy7YRObKky96JOgtbOPWRvRiDjUH+rt4G+ZhXr 4JvlhIvMaxaLf1B2jXV2JbnW5sdOkJHPVypSQx+qmkpMNg0DYz8jY4XMX+eFJWvVxIVFGz/F9Ix JWO8yKSfGlzu/vSUSeFJTFpMvrDBrtzCxM6Sv3D7bcWFVqDi9DlzGbeBH0M3lSRibrH+Z/eKUFd s2bAegfBSNOuOZ7esBtAZ/tsKVNlU5oFz7bh5zQ0qiTfTHGJuOD24Hguorn1/XSX4usesijpk9d HjTuYPny/llumvlvasTyWrvoap40W83P68+ot6xvh4FFncY+K/D0Zz7WABxnRQid6GOMZahKY2f zvMYivKSSj5ehS4zUVYW1Qk3sWjGE0WECHOA== X-Google-Smtp-Source: AGHT+IFh6MHlnfdeuyIQhGXAgbvGbwc5h0gzPosg27hkAGLObIWCHeMNKRns6cTmzbKBe429Zdu5Lg== X-Received: by 2002:a17:906:7308:b0:b76:31e6:2ee1 with SMTP id a640c23a62f3a-b7a242b0b18mr379245266b.18.1765067858559; Sat, 06 Dec 2025 16:37:38 -0800 (PST) Received: from foxbook (bfg212.neoplus.adsl.tpnet.pl. [83.28.44.212]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b79fe78c9ebsm614453566b.5.2025.12.06.16.37.37 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Sat, 06 Dec 2025 16:37:38 -0800 (PST) Date: Sun, 7 Dec 2025 01:37:34 +0100 From: Michal Pecio To: Johannes =?UTF-8?B?QnLDvGRlcmw=?= Cc: linux-usb@vger.kernel.org, gregkh@linuxfoundation.org Subject: Re: [PATCH] usb: core: add USB_QUIRK_NO_BOS for devices that hang on BOS descriptor Message-ID: <20251207013734.4e99331f.michal.pecio@gmail.com> In-Reply-To: <20251207000007.11631-1-johannes.bruederl@gmail.com> References: <20251207000007.11631-1-johannes.bruederl@gmail.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Sun, 7 Dec 2025 01:00:07 +0100, Johannes Br=C3=BCderl wrote: > Add USB_QUIRK_NO_BOS quirk flag to skip requesting the BOS descriptor > for devices that cannot handle it. >=20 > Add Elgato 4K X (0fd9:009b) to the quirk table. This device hangs when > the BOS descriptor is requested at SuperSpeed Plus (10Gbps). >=20 > Link: https://bugzilla.kernel.org/show_bug.cgi?id=3D220027 > Signed-off-by: Johannes Br=C3=BCderl IIRC what we found in this bug is that the device will happily respond to BOS descriptor requests issued by lsusb after it's enumerated. So it appears that (only when running at 10G, wtf) the device expects something to happen before it is able to produce this descriptor. And apparently Linux is doing things in different order than certain other operating system supported by the vendor. But the reporter simply applied a patch similar to yours and lost interest in debugging any further. And unfortunately WinPCAP fails to capture most of enumeration process, so I don't know how that other software is doing it. Regards, Michal