From patchwork Wed May 13 09:50:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11545553 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 479D4913 for ; Wed, 13 May 2020 09:50:23 +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 2FAEC20575 for ; Wed, 13 May 2020 09:50:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2FAEC20575 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 5DB9889F77; Wed, 13 May 2020 09:50:22 +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 9E54E89F77 for ; Wed, 13 May 2020 09:50:20 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from build.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 21184201-1500050 for ; Wed, 13 May 2020 10:50:17 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 13 May 2020 10:50:16 +0100 Message-Id: <20200513095016.10882-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Subject: [Intel-gfx] [CI] drm/i915/gt: Reset execlists registers before HWSP 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" Upon gt resume, we first poison then sanitize the engine. However, our testing shows that gen9 will very rarely retain the poisoned value from the HWSP mappings of the execlists status registers. This suggests that it is reading back from the HWSP, so rejig the register reset. v2: Maybe RING_CONTEXT_STATUS_PTR is write masked. Signed-off-by: Chris Wilson Acked-by: Mika Kuoppala --- drivers/gpu/drm/i915/gt/intel_lrc.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 15716e4d6b76..21db0566dad7 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -3938,6 +3938,14 @@ static void reset_csb_pointers(struct intel_engine_cs *engine) ring_set_paused(engine, 0); + /* + * Sometimes Icelake forgets to reset its pointers on a GPU reset. + * Bludgeon them with a mmio update to be sure. + */ + ENGINE_WRITE(engine, RING_CONTEXT_STATUS_PTR, + 0xffff << 16 | reset_value << 8 | reset_value); + ENGINE_POSTING_READ(engine, RING_CONTEXT_STATUS_PTR); + /* * After a reset, the HW starts writing into CSB entry [0]. We * therefore have to set our HEAD pointer back one entry so that @@ -3951,16 +3959,15 @@ static void reset_csb_pointers(struct intel_engine_cs *engine) WRITE_ONCE(*execlists->csb_write, reset_value); wmb(); /* Make sure this is visible to HW (paranoia?) */ - /* - * Sometimes Icelake forgets to reset its pointers on a GPU reset. - * Bludgeon them with a mmio update to be sure. - */ + invalidate_csb_entries(&execlists->csb_status[0], + &execlists->csb_status[reset_value]); + + /* Once more for luck and our trusty paranoia */ ENGINE_WRITE(engine, RING_CONTEXT_STATUS_PTR, reset_value << 8 | reset_value); ENGINE_POSTING_READ(engine, RING_CONTEXT_STATUS_PTR); - invalidate_csb_entries(&execlists->csb_status[0], - &execlists->csb_status[reset_value]); + GEM_BUG_ON(READ_ONCE(*execlists->csb_write) != reset_value); } static void execlists_sanitize(struct intel_engine_cs *engine)