From patchwork Fri Sep 17 23:38:18 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Brost X-Patchwork-Id: 12503119 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 36CDEC433FE for ; Fri, 17 Sep 2021 23:43:22 +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 003A161152 for ; Fri, 17 Sep 2021 23:43:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 003A161152 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com 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 83B0B6EEA8; Fri, 17 Sep 2021 23:43:20 +0000 (UTC) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1EFED6EEA7; Fri, 17 Sep 2021 23:43:19 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10110"; a="221014319" X-IronPort-AV: E=Sophos;i="5.85,302,1624345200"; d="scan'208";a="221014319" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Sep 2021 16:43:18 -0700 X-IronPort-AV: E=Sophos;i="5.85,302,1624345200"; d="scan'208";a="473271932" Received: from jons-linux-dev-box.fm.intel.com ([10.1.27.20]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Sep 2021 16:43:18 -0700 From: Matthew Brost To: , Subject: [PATCH] drm/i915: fix blank screen booting crashes Date: Fri, 17 Sep 2021 16:38:18 -0700 Message-Id: <20210917233818.33659-1-matthew.brost@intel.com> X-Mailer: git-send-email 2.32.0 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" From: Hugh Dickins 5.15-rc1 crashes with blank screen when booting up on two ThinkPads using i915. Bisections converge convincingly, but arrive at different and surprising "culprits", none of them the actual culprit. netconsole (with init_netconsole() hacked to call i915_init() when logging has started, instead of by module_init()) tells the story: kernel BUG at drivers/gpu/drm/i915/i915_sw_fence.c:245! with RSI: ffffffff814d408b pointing to sw_fence_dummy_notify(). I've been building with CONFIG_CC_OPTIMIZE_FOR_SIZE=y, and that function needs to be 4-byte aligned. v2: (Jani Nikula) - Change BUG_ON to WARN_ON Fixes: 62eaf0ae217d ("drm/i915/guc: Support request cancellation") Signed-off-by: Hugh Dickins Signed-off-by: Matthew Brost Reviewed-by: Matthew Brost --- drivers/gpu/drm/i915/gt/intel_context.c | 1 + drivers/gpu/drm/i915/i915_sw_fence.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c index ff637147b1a9..f02c2202da9d 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.c +++ b/drivers/gpu/drm/i915/gt/intel_context.c @@ -362,6 +362,7 @@ static int __intel_context_active(struct i915_active *active) return 0; } +__aligned(4) /* Respect the I915_SW_FENCE_MASK */ static int sw_fence_dummy_notify(struct i915_sw_fence *sf, enum i915_sw_fence_notify state) { diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c index c589a681da77..1217b124c1d0 100644 --- a/drivers/gpu/drm/i915/i915_sw_fence.c +++ b/drivers/gpu/drm/i915/i915_sw_fence.c @@ -14,8 +14,10 @@ #if IS_ENABLED(CONFIG_DRM_I915_DEBUG) #define I915_SW_FENCE_BUG_ON(expr) BUG_ON(expr) +#define I915_SW_FENCE_WARN_ON(expr) WARN_ON(expr) #else #define I915_SW_FENCE_BUG_ON(expr) BUILD_BUG_ON_INVALID(expr) +#define I915_SW_FENCE_WARN_ON(expr) BUILD_BUG_ON_INVALID(expr) #endif static DEFINE_SPINLOCK(i915_sw_fence_lock); @@ -242,7 +244,7 @@ void __i915_sw_fence_init(struct i915_sw_fence *fence, const char *name, struct lock_class_key *key) { - BUG_ON(!fn || (unsigned long)fn & ~I915_SW_FENCE_MASK); + I915_SW_FENCE_WARN_ON(!fn || (unsigned long)fn & ~I915_SW_FENCE_MASK); __init_waitqueue_head(&fence->wait, name, key); fence->flags = (unsigned long)fn;