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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 04A16C433E6 for ; Tue, 2 Feb 2021 20:05:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C139764E51 for ; Tue, 2 Feb 2021 20:05:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240312AbhBBUF0 (ORCPT ); Tue, 2 Feb 2021 15:05:26 -0500 Received: from mail.kernel.org ([198.145.29.99]:36544 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232715AbhBBNnN (ORCPT ); Tue, 2 Feb 2021 08:43:13 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4110F64F69; Tue, 2 Feb 2021 13:40:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612273216; bh=SuaqPjJeRzovVcZthpTQGI6mBv/Tovh+I0x//MkMnWE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X2wxaZw9nJXI6iVIUqL4x7ZqF+VJcNbCRkahAwPWMRJ27i0iBIBMaRFmeyKICJY8X N9eYdE+50WQ9M1oJCemrFqOiRnbUjHECHXLRRlzXmeAwszgGhSdcRt0ekSfQThgfbU 8P81m3OoeB6MYqbNpXgbnX5DLsj1aOYqVguOVKVY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chris Wilson , Matthew Auld , Tvrtko Ursulin , Jani Nikula Subject: [PATCH 5.10 024/142] drm/i915: Always flush the active worker before returning from the wait Date: Tue, 2 Feb 2021 14:36:27 +0100 Message-Id: <20210202132958.712870599@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210202132957.692094111@linuxfoundation.org> References: <20210202132957.692094111@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chris Wilson commit f6e98a1809faa02f40e0d089d6cfc1aa372a34c0 upstream. The first thing the active retirement worker does is decrement the i915_active count. The first thing we do during i915_active_wait is try to increment the i915_active count, but only if already active [non-zero]. The wait may see that the retirement is already started and so marked the i915_active as idle, and skip waiting for the retirement handler. However, the caller of i915_active_wait may immediately free the i915_active upon returning (e.g. i915_vma_destroy) so we must not return before the concurrent access from the worker is completed. We must always flush the worker. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2473 Fixes: 274cbf20fd10 ("drm/i915: Push the i915_active.retire into a worker") Signed-off-by: Chris Wilson Cc: Matthew Auld Cc: Tvrtko Ursulin Cc: # v5.5+ Reviewed-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20210121232807.16618-1-chris@chris-wilson.co.uk (cherry picked from commit 977a372e972cb42799746c284035a33c64ebace9) Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c index 10a865f3dc09..9ed19b8bca60 100644 --- a/drivers/gpu/drm/i915/i915_active.c +++ b/drivers/gpu/drm/i915/i915_active.c @@ -631,24 +631,26 @@ static int flush_lazy_signals(struct i915_active *ref) int __i915_active_wait(struct i915_active *ref, int state) { - int err; - might_sleep(); - if (!i915_active_acquire_if_busy(ref)) - return 0; - /* Any fence added after the wait begins will not be auto-signaled */ - err = flush_lazy_signals(ref); - i915_active_release(ref); - if (err) - return err; + if (i915_active_acquire_if_busy(ref)) { + int err; - if (!i915_active_is_idle(ref) && - ___wait_var_event(ref, i915_active_is_idle(ref), - state, 0, 0, schedule())) - return -EINTR; + err = flush_lazy_signals(ref); + i915_active_release(ref); + if (err) + return err; + if (___wait_var_event(ref, i915_active_is_idle(ref), + state, 0, 0, schedule())) + return -EINTR; + } + + /* + * After the wait is complete, the caller may free the active. + * We have to flush any concurrent retirement before returning. + */ flush_work(&ref->work); return 0; }