From patchwork Fri Apr 5 13:28:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Janusz Krzysztofik X-Patchwork-Id: 10887371 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1206A1575 for ; Fri, 5 Apr 2019 13:28:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EF1E2289F1 for ; Fri, 5 Apr 2019 13:28:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E394B28B6B; Fri, 5 Apr 2019 13:28:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 7B471289F1 for ; Fri, 5 Apr 2019 13:28:19 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F07AC89E57; Fri, 5 Apr 2019 13:28:16 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id 590B389E57; Fri, 5 Apr 2019 13:28:16 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Apr 2019 06:28:15 -0700 X-IronPort-AV: E=Sophos;i="5.60,312,1549958400"; d="scan'208";a="220877453" Received: from jkrzyszt-desk.igk.intel.com ([172.22.244.18]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Apr 2019 06:28:12 -0700 From: Janusz Krzysztofik To: Joonas Lahtinen , Jani Nikula , Rodrigo Vivi Subject: [PATCH v2] drm/i915: Don't panic on non-empty list of free cachelines Date: Fri, 5 Apr 2019 15:28:06 +0200 Message-Id: <20190405132806.8508-1-janusz.krzysztofik@linux.intel.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Janusz Krzysztofik , David Airlie , intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, michal.wajdeczko@intel.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Janusz Krzysztofik If there are active users of a device during driver unbind, the driver now panics on non-empty list of free cachelines. By design, cachelines which are not in use are kept on a list of free cachelines associated with a timeline and removed from that list either when in use or when the timeline is destroyed. Timelines in turn are assigned to open file descriptors. As long as a device file is open, its associated timeline with its list of free cachelines will be hopefully destroyed on device close, either while outstanding execlists are destroyed or on i915_timeline_put() called directly, so as long as device file descriptors are protected from unwanted user activities by the device being marked unplugged, there should be no reason to panic. Moreover, timeline mutex which is destroyed right after the check for emptyness of a free cacheline list succeeds is never used to protect that list, only a list of active cachelines, so it can be freely destroyed even if the former is not empty. Since the desired behavior is to clean up active contexts first, unpinning the contexts and resources, and so letting the timeline be freed, the panic is there to say that i915_timelines_fini() is called to early. Don't remove the check completely then but convert it from the BUG() to a WARN() so the indication a long term fix is needed is still given. Signed-off-by: Janusz Krzysztofik --- drivers/gpu/drm/i915/i915_timeline.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_timeline.c b/drivers/gpu/drm/i915/i915_timeline.c index b2202d2e58a2..965fd3052b25 100644 --- a/drivers/gpu/drm/i915/i915_timeline.c +++ b/drivers/gpu/drm/i915/i915_timeline.c @@ -325,7 +325,7 @@ void i915_timelines_fini(struct drm_i915_private *i915) struct i915_gt_timelines *gt = &i915->gt.timelines; GEM_BUG_ON(!list_empty(>->active_list)); - GEM_BUG_ON(!list_empty(>->hwsp_free_list)); + GEM_WARN_ON(!list_empty(>->hwsp_free_list)); mutex_destroy(>->mutex); }