From patchwork Thu Nov 9 19:21:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vinay Belgaumkar X-Patchwork-Id: 13451661 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 2DFD9C4332F for ; Thu, 9 Nov 2023 19:22:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 97D4F10E8F5; Thu, 9 Nov 2023 19:22:28 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4390810E8F5; Thu, 9 Nov 2023 19:22:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1699557746; x=1731093746; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=gMq2G7QSqB2DdHSPl2LLgATi9RHBVk93YEEpZDfk7+c=; b=BDsrEe99rV2EMwAEqFWN6kTQM6o7Pl6n46J5BItDMA1Jd8/aEco6ktaz VRZ2sj1wcY/yRLYQqUCj37GhgjX/SNWlPuZcPbRu/r0XliX6CLNgsbG9V wd3kBHOCmDnDvJ9Pu1WHfd1t3KJb88XmVH5wB/QYiT/PpKtYzce8NuDoN AeHRXZFrTDLxUewdDFmBR+RXcjAIieK22V0xVEAnTQno8FK4u5jUR0Rop Tvw2VPG6U+VNdZSD1cIDZ6PQ+AaD8r+I/TV0vO0CYyZEzzy8CY7yBkii5 ZDDzpm4bQq0mJtR64v7nBeQSV4KEJqv5mQHdyoI1OI2CsQ/48QCVNA9lW g==; X-IronPort-AV: E=McAfee;i="6600,9927,10889"; a="3095126" X-IronPort-AV: E=Sophos;i="6.03,290,1694761200"; d="scan'208";a="3095126" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Nov 2023 11:22:19 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10889"; a="907233220" X-IronPort-AV: E=Sophos;i="6.03,290,1694761200"; d="scan'208";a="907233220" Received: from vbelgaum-ubuntu.fm.intel.com ([10.1.27.27]) by fmsmga001.fm.intel.com with ESMTP; 09 Nov 2023 11:22:18 -0800 From: Vinay Belgaumkar To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Date: Thu, 9 Nov 2023 11:21:48 -0800 Message-Id: <20231109192148.475156-1-vinay.belgaumkar@intel.com> X-Mailer: git-send-email 2.38.1 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH] drm/i915: Read a shadowed mmio register for ggtt flush 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" We read RENDER_HEAD as a part of the flush. If GT is in deeper sleep states, this could lead to read errors since we are not using a forcewake. Safer to read a shadowed register instead. Cc: John Harrison Cc: Daniele Ceraolo Spurio Signed-off-by: Vinay Belgaumkar Reviewed-by: Radhakrishna Sripada --- drivers/gpu/drm/i915/gt/intel_gt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c index ed32bf5b1546..ea814ea5f700 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt.c +++ b/drivers/gpu/drm/i915/gt/intel_gt.c @@ -451,7 +451,7 @@ void intel_gt_flush_ggtt_writes(struct intel_gt *gt) spin_lock_irqsave(&uncore->lock, flags); intel_uncore_posting_read_fw(uncore, - RING_HEAD(RENDER_RING_BASE)); + RING_TAIL(RENDER_RING_BASE)); spin_unlock_irqrestore(&uncore->lock, flags); } }