From patchwork Mon Oct 4 22:06:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Brost X-Patchwork-Id: 12534985 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 7A7EAC433F5 for ; Mon, 4 Oct 2021 22:12:38 +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 4D5A56136F for ; Mon, 4 Oct 2021 22:12:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4D5A56136F 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 2DCEB892EE; Mon, 4 Oct 2021 22:11:37 +0000 (UTC) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id 74BDC6E223; Mon, 4 Oct 2021 22:11:31 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10127"; a="248854264" X-IronPort-AV: E=Sophos;i="5.85,347,1624345200"; d="scan'208";a="248854264" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Oct 2021 15:11:30 -0700 X-IronPort-AV: E=Sophos;i="5.85,347,1624345200"; d="scan'208";a="487735460" Received: from jons-linux-dev-box.fm.intel.com ([10.1.27.20]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Oct 2021 15:11:30 -0700 From: Matthew Brost To: , Cc: , Date: Mon, 4 Oct 2021 15:06:15 -0700 Message-Id: <20211004220637.14746-5-matthew.brost@intel.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211004220637.14746-1-matthew.brost@intel.com> References: <20211004220637.14746-1-matthew.brost@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 04/26] drm/i915/guc: Don't call switch_to_kernel_context with GuC submission 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" 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;