From patchwork Fri Jan 17 11:06:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11338787 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E5DA1138D for ; Fri, 17 Jan 2020 11:06:20 +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 CE4842082F for ; Fri, 17 Jan 2020 11:06:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CE4842082F 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=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 673486F500; Fri, 17 Jan 2020 11:06:20 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id BF5196F500 for ; Fri, 17 Jan 2020 11:06:19 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 19914539-1500050 for multiple; Fri, 17 Jan 2020 11:06:04 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Fri, 17 Jan 2020 11:06:02 +0000 Message-Id: <20200117110603.2982286-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.25.0 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH] drm/i915: Satisfy smatch that a loop has at least one iteration X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Smatch worries that the engine->mask may be 0 leading to the loop being shortcircuited leaving the next pointer unset, drivers/gpu/drm/i915/i915_active.c:667 i915_active_acquire_preallocate_barrier() error: uninitialized symbol 'next'. Assert that mask is not 0 and smatch can then verify that next must be initialised before use. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Matthew Auld --- drivers/gpu/drm/i915/i915_active.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c index f3da5c06f331..ace55d5d4ca7 100644 --- a/drivers/gpu/drm/i915/i915_active.c +++ b/drivers/gpu/drm/i915/i915_active.c @@ -621,6 +621,7 @@ int i915_active_acquire_preallocate_barrier(struct i915_active *ref, * We can then use the preallocated nodes in * i915_active_acquire_barrier() */ + GEM_BUG_ON(!mask); for_each_engine_masked(engine, gt, mask, tmp) { u64 idx = engine->kernel_context->timeline->fence_context; struct active_node *node;