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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C79CFC433F5 for ; Thu, 4 Nov 2021 08:05:27 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 80E7E60EB4 for ; Thu, 4 Nov 2021 08:05:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 80E7E60EB4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=bugzilla.kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AB24F6EB8F; Thu, 4 Nov 2021 08:05:26 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by gabe.freedesktop.org (Postfix) with ESMTPS id 97CF26EB8F for ; Thu, 4 Nov 2021 08:05:25 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPS id 66CAC61108 for ; Thu, 4 Nov 2021 08:05:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636013125; bh=Q66vTT5WV72V+21UgQybVKMReB382F9Spbw6PX6ZoxY=; h=From:To:Subject:Date:In-Reply-To:References:From; b=fL7xgeW/W3GbFRV1L8xS7mZt19m4mSG3qNwthGvDl5GdVFJkJf/gyjL7lV+AbWoNY gsud2iYum+q3YQrjZoMuBzfIoE167HrpLeP7c+sUggF3RTF57+Vb8Ukd7xNtO4DMvS VtQKSKUavDHWTVSYjjLxJpKqsHH4HMZLmenQrjPyt6B4yozSeUrQBL4yLBZkBa36PU 23oM2pkvnt8N7qfEpZMGJ5u9AiMMBR+hkRsDhXdXb/lkPIKjGGyrMNfN45STttoPzo Gv3L0WkkT4dHogHVKzWMTkWjoaFw37URZ5ZLvjy+NYdIX7lOWrsMmM3JSljmtwh4Yj MLtnposKpI0zA== From: bugzilla-daemon@bugzilla.kernel.org To: dri-devel@lists.freedesktop.org Subject: [Bug 214621] WARNING: CPU: 3 PID: 521 at drivers/gpu/drm/ttm/ttm_bo.c:409 ttm_bo_release+0xb64/0xe40 [ttm] Date: Thu, 04 Nov 2021 08:05:24 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo drivers_video-dri@kernel-bugs.osdl.org X-Bugzilla-Product: Drivers X-Bugzilla-Component: Video(DRI - non Intel) X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: christian.koenig@amd.com X-Bugzilla-Status: RESOLVED X-Bugzilla-Resolution: DUPLICATE X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: drivers_video-dri@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" https://bugzilla.kernel.org/show_bug.cgi?id=3D214621 --- Comment #9 from Christian K=C3=B6nig (christian.koenig@amd.com) --- (In reply to Lang Yu from comment #8) > (In reply to Christian K=C3=B6nig from comment #7) > > Yeah, that won't work. As far as I can see the problem is not inside > amdgpu, > > but rather inside the driver which is importing buffers from amdgpu. >=20 > At least, we should call drm_prime_gem_destroy() to detach dma-buf(if > exists) before WARN_ON_ONCE(bo->pin_count). Nope, that's incorrect. You are mixing things up here. This is for the case when amdgpu imports a buffer, but the warning happens = when amdgpu exports a buffer. And on import you indeed only want to drop the attachment after the BO is really destroyed or not when the GEM handle is destroyed. Otherwise you cou= ld potentially unmap memory while it is still used by the hardware. > And do you think if clients don't unmap/detach amdgpu dma-buf properly, > should amdgpu do that work? Thanks! No. That rather looks like the importer is messing up some reference count = and forgets to destroy the attachment before the dma-buf. There is absolutely nothing the exporter can do in that situation. There is the slightly chance that the bug is indeed somewhere inside amdgpu= or the dma-buf framework itself (Michel and I are huntin a similar issue at the moment), but it does work with other driver combinations. --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=