From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-102.mailbox.org (mout-p-102.mailbox.org [80.241.56.152]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 412EA473C6D; Mon, 28 Sep 2026 08:33:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.152 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790584387; cv=none; b=Fy9RMBLssWAfy5Bz5ruo7qqMYsR9XOGQk47fDYmq+9JOh4Z5GN7+1T+4r6QIFyCd+MqSNhgenXbD2yTpV+w4l0c0M7RjhbHzSml4ytuL+iY4smhJk7iIvYLqyUzle3xz+A03n47TUonWR167dp/pcFq0ybSRHHv199FGJhDSt0Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790584387; c=relaxed/simple; bh=dPQiJZRjfltzxHJi5k9HU87/LqeEBeKq9w573KqY3SI=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=aAeVHBTUtYmB284qh9IRDs3pDty6kiF7LgRb4MA08yio5VPEqgfAvXvubCf/uksZlorU+TjtZhlhfwBWK3y208jBBHi3xoExkk31OEnPv02uFPBHfZvdQlsNKXqY+NgKlxSBUO1vk3KRviMNSYlWjc7Awr4xa/ApyRXypPtPEpI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b=qZHnr2GI; arc=none smtp.client-ip=80.241.56.152 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) header.d=mailbox.org header.i=@mailbox.org header.b="qZHnr2GI" Received: from smtp1.mailbox.org (unknown [10.196.197.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-102.mailbox.org (Postfix) with ESMTPS id 4htZM10m9RzKvhy; Mon, 28 Sep 2026 10:33:01 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1790584381; 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=dPQiJZRjfltzxHJi5k9HU87/LqeEBeKq9w573KqY3SI=; b=qZHnr2GII/3uXBtgXhk9jwe1cKSNnnxbS1eS0cUNSfxgvLUx0tdxWEI3/YaMPnq5pqdjTl 0pLd+FSsXbJl37nBHb0y7m8KXaqXkeE/QW3Jlw/QhJfyZxSaOls+h39hYAvx2brTTcqRTZ EsCb+b4kG1+ZHZsuoSuxjT2fOZwrNxQGMipPN7+RIm1grTE02NhaRtQcRtqVka5pBi0QGU aO9Iz1yAfPThuBJFAM40Lg6jpLwDOLJl6HdHcgql/BDT1L7jtYUTsvOy7QEw5y31Tx0n9N od2Jaxa9JV1CTI80iRAiE8t+7JMJwYE3PQoZPFV67UmsSz53C6Fl15T++Ozqsg== Message-ID: Subject: Re: [PATCH] rust: DmaFence: Add better warning through Device reference From: Philipp Stanner Reply-To: phasta@kernel.org To: Danilo Krummrich Cc: phasta@kernel.org, Gary Guo , Alice Ryhl , Sumit Semwal , Christian =?ISO-8859-1?Q?K=F6nig?= , Miguel Ojeda , Boqun Feng , =?ISO-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Trevor Gross , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , Onur =?ISO-8859-1?Q?=D6zkan?= , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 28 Sep 2026 10:32:54 +0200 In-Reply-To: References: <20260925081958.3048112-2-phasta@kernel.org> <37a2858a4687e4d9bbe0aba4c1861b96875c4ed7.camel@mailbox.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MBO-RS-META: 1xuw3zyrf31yye8ku3bcs35ptp84s696 X-MBO-RS-ID: ac8c0f2cdd2425f6d3a On Mon, 2026-09-28 at 10:11 +0200, Danilo Krummrich wrote: > On Mon Sep 28, 2026 at 9:52 AM CEST, Philipp Stanner wrote: > > > > So I suppose we agree that a warning is fine. It won't fire in JQ > > > > anyways, but might benefit others. > > >=20 > > > What scenario are you thinking of? > >=20 > > Drivers doing "rather questionable" things, like we've seen a great > > many times already ;) > >=20 > > Note that the dma_fence backend fires a WARN_ON if a fence is freed > > unsignaled, too, for the same reason. > >=20 > > Life finds a way. >=20 > I'd rather you engage with the arguments I made above and give a concrete > example of how it "might benefit others", instead of resorting to know-it= -all > platitudes. Stating that I cannot know nor conceive all possible patterns and misbehaviors is quite literally me acknowledging that I do *not* "know it all". With this patch I was just trying to accommodate your post-merge request for replacing pr_ with dev_err() or WARN_ON. If you think neither is actually necessary, that's also fine by me. P.