From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=80.241.56.152 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793107109; b=w9pCiJ+zAQVEEE+PWbO2eaRZrtdw5egDT9Y1J2An2WsMtz6mIbrXOj51IsgF0gSuRKoG rAQkRAyrgaVW5vMvlx2lPK/s0kPhfa3XVy/z4A08ntF4E6/NibtfHexULEkT624Ci6225 f1bmcM29tCV70wFfGaZcVdwGCjChESCgzPNvKsSFdSrj3wUuSRSra4YBn19/Ns15l2Cu5 7szKsrupiqxwKK/YozhpkYPuZp8H4VO+UL9gFTOKaH6YeI4JTTZcwMQbKPmW92ryxYyVk Lh6d/IxwnDXLLpaRpWTNJ6ykzgg8LnrAw7/Ade3RVHR/7yPMQtprt/sWD/jbqZT3RPw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793107109; h=DMARC-Filter:Received:DKIM-Signature:Message-ID:Subject:From: Reply-To:To:Cc:Date:In-Reply-To:References:Content-Type: Content-Transfer-Encoding:User-Agent:MIME-Version:X-MBO-RS-META: X-MBO-RS-ID; bh=PWeOBryevCm8q/A7sxlX/iP0oFz7HX9qKQxKArV12Iw=; b=OLJAkDMmQIiW8b6cj/IzRog3QFMzR/1ftBhyRzRilVxXVLLthqU73br24KOnfgYexWCT i1SJwEJnG3oN6y20Lb40geX0HaFISLucCiWfjACcnikbR4FsRtPfdXh61wkYvc0EN3PTW ssKT3tu1ANDAxcw7BUvv/jbacQcsvJYX7LwEJR7nhT0oGFuyQ2EJlqc/drv75g+ZvjH9l bzgIJ9kTS0Io8awKfbnkfxKcwvldAGnJSohyhQFNZR9auh9gNFrMv4vMXnOk7SUC7QTrZ ll912ao78MDgp6rOfJLnvJ4EX0htCDO9GrJKnH1edKkLHVoVSdZEvLboWIDs+g3RyWg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass header.d=mailbox.org header.i=@mailbox.org header.a=rsa-sha256 header.s=mail20150812 header.b=iVCr79NK; arc=none smtp.remote-ip=80.241.56.152 Received: from mout-p-102.mailbox.org (mout-p-102.mailbox.org [80.241.56.152]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 12419606A31E; Tue, 27 Oct 2026 13:18:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 12419606A31E Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailbox.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=mailbox.org header.i=@mailbox.org header.a=rsa-sha256 header.s=mail20150812 header.b=iVCr79NK Received: from smtp102.mailbox.org (smtp102.mailbox.org [IPv6:2001:67c:2050:b231:465::102]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519MLKEM768 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-102.mailbox.org (Postfix) with ESMTPS id 4jDWJr2jMBzKpLX; Tue, 27 Oct 2026 14:18:20 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1793107100; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PWeOBryevCm8q/A7sxlX/iP0oFz7HX9qKQxKArV12Iw=; b=iVCr79NK6XGQ6EgNpNOD2bIXbXL4I31nNsALqsgJRAan4PCZUas/ziri01k+UiVvLsQycr jEGy6QljBosVW5Jqu3A3FRH9PvEPpuR1SGd/VF9yKM8tiw3qKMJDMTnIN61hfHzO9OAalg +R4lzNj7N3ZHiyQkid3xUbPsvyYN6df7DO+vf2+mhbILym7f7VNh7w6qtP3E8pLywHmgky PNA+zG+e/z3TjI0CHMJMq+oEv4xqQ4um8e04VeTmBtozNA74R3z1gtrHt5WAgK+sTPgwlY jVLHV3f1canVotp7+7KSY9bxJDhgRLuFMtxsVimGTIwXsp7syZC2oZLllN1x6w== Message-ID: Subject: Re: [PATCH] drm/amdgpu: Harden against potential deadlock From: Philipp Stanner Reply-To: phasta@kernel.org To: Christian =?ISO-8859-1?Q?K=F6nig?= , Felix Kuehling , Philipp Stanner , Alex Deucher , David Airlie , Simona Vetter , Sumit Semwal Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Date: Tue, 27 Oct 2026 14:18:16 +0100 In-Reply-To: <1ed5c075-c66a-4144-b23b-a9d80e1fc2c1@amd.com> References: <20261026141541.469727-2-phasta@kernel.org> <1ed5c075-c66a-4144-b23b-a9d80e1fc2c1@amd.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 (3.60.2-2.fc44) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-MBO-RS-META: buiiipye989ra698z48roho9cbycqgfu X-MBO-RS-ID: 7b35dd1fa6a48d1be36 On Tue, 2026-10-27 at 12:51 +0100, Christian K=C3=B6nig wrote: > On 10/26/26 19:31, Felix Kuehling wrote: > > We don't implement ops->signaled, and we explicitly signal the > > fence from SW with dma_fence_signal or dma_fence_check_and_signal. > > So the signaled flag should be the only thing that needs to be > > checked. The flag is only set while holding the fence lock, and > > checked while holding the fence lock. So in theory, relying on the > > check in __dma_fence_enable_signaling should be safe. >=20 > I actually had a patch to remove that one send out month ago already, > it was just never merged. >=20 > The call absolutely doesn't make sense since the ops->signaled > callback isn't implemented and the bit tested before the enable > signaling callback called. >=20 > I can take care and push the removal to amd-staging-drm-next when I > find time. OK, but put me on Cc please. I could need that change for my other dma_fence-ish work. I would post the removal as a v2, too, if I don't hear from you mid-term Greetings, Philipp