From patchwork Wed Oct 13 20:42:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Brost X-Patchwork-Id: 12557245 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D503C433EF for ; Wed, 13 Oct 2021 20:56:31 +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 6F7CB61139 for ; Wed, 13 Oct 2021 20:56:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6F7CB61139 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 211616EB71; Wed, 13 Oct 2021 20:56:01 +0000 (UTC) Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTPS id BB6996EB6C; Wed, 13 Oct 2021 20:55:57 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10136"; a="214690376" X-IronPort-AV: E=Sophos;i="5.85,371,1624345200"; d="scan'208";a="214690376" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2021 13:47:19 -0700 X-IronPort-AV: E=Sophos;i="5.85,371,1624345200"; d="scan'208";a="524782695" Received: from jons-linux-dev-box.fm.intel.com ([10.1.27.20]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2021 13:47:19 -0700 From: Matthew Brost To: , Cc: Subject: [PATCH 04/25] drm/i915/guc: Don't call switch_to_kernel_context with GuC submission Date: Wed, 13 Oct 2021 13:42:10 -0700 Message-Id: <20211013204231.19287-5-matthew.brost@intel.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211013204231.19287-1-matthew.brost@intel.com> References: <20211013204231.19287-1-matthew.brost@intel.com> 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" Calling switch_to_kernel_context isn't needed if the engine PM reference is taken while all user contexts are pinned as if don't have PM ref that guarantees that all user contexts scheduling is disabled. By not calling switch_to_kernel_context we save on issuing a request to the engine. v2: (Daniel Vetter) - Add FIXME comment about pushing switch_to_kernel_context to backend v3: (John Harrison) - Update commit message - Fix workding comment Signed-off-by: Matthew Brost Reviewed-by: Daniel Vetter Reviewed-by: John Harrison --- drivers/gpu/drm/i915/gt/intel_engine_pm.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c index dacd62773735..a1334b48dde7 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c @@ -162,6 +162,19 @@ static bool switch_to_kernel_context(struct intel_engine_cs *engine) unsigned long flags; bool result = true; + /* + * This is execlist specific behaviour intended to ensure the GPU is + * idle by switching to a known 'safe' context. With GuC submission, the + * same idle guarantee is achieved by other means (disabling + * scheduling). Further, switching to a 'safe' context has no effect + * with GuC submission as the scheduler can just switch back again. + * + * FIXME: Move this backend scheduler specific behaviour into the + * scheduler backend. + */ + if (intel_engine_uses_guc(engine)) + return true; + /* GPU is pointing to the void, as good as in the kernel context. */ if (intel_gt_is_wedged(engine->gt)) return true;