From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793406122; b=stHUOruhEv9LtGhThCs5Mr5wcZe0dN6f/kkdBTx4nC1sajUkB0zm+AqqmDGVm0Dg2UNh lYa2sXJqlfznL1GthQTofBSpwOnxQlnMMQD/m8Ua3vG7kC/lthBsge4B13kY6ow6knC3a OUYrU3GGNig0Gp3FPeh+LK8xFrYblKJ6c1r8gS3F5TgQac7O9CU1htVoxL1ni8vuRHNyw 16bSXv3pzWzS9mig6W+V0gsHSq5dBesRG7yTBTsVw0DjpAG7VBrykL6nkT4/USxW/p+Qi /nLmXZsll7qfteBnHONXptk3iOuLNU1ShzM1hu2s6gisiE+w3+m1EpApA2qWRu4uIKQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793406122; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=P+gXizfPfu6Nh2f/AlrJPmbARrZvgx92P+LP+P00FOo=; b=Dbrh3GkJGcBYmxZfTYfrVE7dTB1RvgnLUlVseMmyiBcatpntCosDgjwwAN4u1gDt1Wz5 EVJuVzkX7JOtH9ygv4DwLTZj7CFfPRmp58sWBgOg4OW5hOdVslQccUxKSLt7MxikubkdV ljJgfrKLwALlGASlDonpb7hwXnVVQMhZiP0wEJRGDtJWzWXvUnfCbMhDbAPXUCMK2/0K0 wqqJqVocg5zf7dR+3ahN6h78t10lrwLC/T/hVqdMWwKq2+taTX/WS5/UgOBppDmDNPhA+ CpxuVNDIbR8THxvHZGqGzWZrWrhK+A2KaImRhxkQWiMpQe/0ha3mu+HGjBA+BFVZYxA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=SS4yo4Xb; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7A0E9606A31A for ; Sat, 31 Oct 2026 00:22:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=SS4yo4Xb Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33ECF1F000C1; Sat, 31 Oct 2026 00:22:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793406122; bh=P+gXizfPfu6Nh2f/AlrJPmbARrZvgx92P+LP+P00FOo=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=SS4yo4Xb0Th0c3HIMZU+azJlejF5gVAduvNhs8MKoMup9uqEyZWE6FdnHmesYnjzg znsJimshrgV3NJEAdeXKwtpzXG1AfrjpcHhro4Up5HVSH+FoBaeE824nYO7U5zSuiU 534ZFtWmlbiSLWWf92Tw5AL8/Z5n7/U2fwq0gtJPi/EcXPDYLjqS1gVT+8ELFpTXht VkFPrv32JlRzA7Vs8RU4THO2DmzZl110sw/Z6FGcADqliA4NrMnyfTUBbkyRvafXg9 dT0R93G66K7AHXvYRzukCRIFqs5MStdlPs7nV3UvLf2wlimJIsJDPUA/XPmNg9ZeB8 Vr/bso9LCMsQQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH RFC] drm/dp_tunnel: Allow BWA when the DP IN adapter does not advertise it Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?RGllZ28gTm9ndcOqcw==?= Cc: linux-usb@vger.kernel.org In-Reply-To: <20261031-dp-tunnel-bwa-flag-v1-1-f94ed3179349@gmail.com> References: <20261031-dp-tunnel-bwa-flag-v1-1-f94ed3179349@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sat, 31 Oct 2026 00:22:01 +0000 X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Diego Nogu=C3=AAs >=20 > On an Alder Lake host (i7-1265U) with a Thunderbolt 4 dock (Dell WD22TB4, > Goshen Ridge) driving two 4K@60 monitors through two DP tunnels, the > monitor whose tunnel is created second is limited to 4K@30. Which monitor > is affected depends only on the order in which they are powered on. >=20 > The thunderbolt driver enables the BW allocation mode (BWA) on both DP IN > adapters: it sets the CM BWA support (DP_USB4_DRIVER_BW_CAPABILITY), a > group ID and the estimated BW. The DP IN adapter, however, never sets > DP_IN_BW_ALLOCATION_MODE_SUPPORT in DP_TUNNELING_CAPABILITIES (0xe000d > reads 0x01), so tunnel_regs_are_valid() rejects the tunnel with: >=20 > DPTUN: A non-zero group ID is only allowed with BWA support >=20 > [ ... ] > Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/17742 > Cc: Imre Deak > Cc: Mika Westerberg > Assisted-by: Claude:claude-opus-5-5 > Signed-off-by: Diego Nogu=C3=AAs Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261031-dp-tunnel-= bwa-flag-v1-1-f94ed3179349@gmail.com?part=3D1