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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD190C433EA for ; Tue, 28 Jul 2020 16:27:51 +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 776E22074F for ; Tue, 28 Jul 2020 16:27:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 776E22074F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 02BDF6E237; Tue, 28 Jul 2020 16:27:50 +0000 (UTC) Received: from fireflyinternet.com (unknown [77.68.26.236]) by gabe.freedesktop.org (Postfix) with ESMTPS id C5EF56E21A; Tue, 28 Jul 2020 16:27:48 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from localhost (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP (TLS) id 21960187-1500050 for multiple; Tue, 28 Jul 2020 17:27:33 +0100 MIME-Version: 1.0 In-Reply-To: References: <20200723172119.17649-1-chris@chris-wilson.co.uk> Subject: Re: [PATCH 1/3] drm: Restore driver.preclose() for all to use From: Chris Wilson To: Daniel Vetter , Dave Airlie Date: Tue, 28 Jul 2020 17:27:33 +0100 Message-ID: <159595365380.28639.1774414370144556112@build.alporthouse.com> User-Agent: alot/0.9 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: , Cc: intel-gfx , dri-devel , Gustavo Padovan , CQ Tang , stable , Daniel Vetter Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Quoting Daniel Vetter (2020-07-27 20:32:45) > On Thu, Jul 23, 2020 at 7:21 PM Chris Wilson wrote: > > > > An unfortunate sequence of events, but it turns out there is a valid > > usecase for being able to free/decouple the driver objects before they > > are freed by the DRM core. In particular, if we have a pointer into a > > drm core object from inside a driver object, that pointer needs to be > > nerfed *before* it is freed so that concurrent access (e.g. debugfs) > > does not following the dangling pointer. > > > > The legacy marker was adding in the code movement from drp_fops.c to > > drm_file.c > > I might fumble a lot, but not this one: > > commit 45c3d213a400c952ab7119f394c5293bb6877e6b > Author: Daniel Vetter > Date: Mon May 8 10:26:33 2017 +0200 > > drm: Nerf the preclose callback for modern drivers Gah, when I going through the history it looked like it appeared out of nowhere. > Also looking at the debugfs hook that has some rather adventurous > stuff going on I think, feels a bit like a kitchensink with batteries > included. If that's really all needed I'd say iterate the contexts by > first going over files, then the ctx (which arent shared anyway) and > the problem should also be gone. Or we could cut out the middlelayer and put the release under the driver control with a call to the drm_release() when the driver is ready. -Chris _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel