From mboxrd@z Thu Jan 1 00:00:00 1970 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=-14.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 5727EC433DB for ; Mon, 18 Jan 2021 12:26:00 +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 C659D2225C for ; Mon, 18 Jan 2021 12:25:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C659D2225C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com 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 1BC1A6E1EC; Mon, 18 Jan 2021 12:25:59 +0000 (UTC) Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id 754F56E1EC for ; Mon, 18 Jan 2021 12:25:57 +0000 (UTC) IronPort-SDR: YtOkwRJTr9PiA7XfZJWKZAKhcfGjFGcIzTl8NZfLY31oTU9Ji05As6SZ+Snlvwcv5wdV2oaVQ5 y87AKfgnV6EQ== X-IronPort-AV: E=McAfee;i="6000,8403,9867"; a="242866652" X-IronPort-AV: E=Sophos;i="5.79,356,1602572400"; d="scan'208";a="242866652" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jan 2021 04:25:54 -0800 IronPort-SDR: JonGdcjR4mhFFAebtQIFkZ7MPy7aeJsdWKkFW4PhSAERWjsz3Xk64K2KpFGjU9jsl3e004KmvJ 6uHuFz30rLuw== X-IronPort-AV: E=Sophos;i="5.79,356,1602572400"; d="scan'208";a="383551290" Received: from nshalit-mobl.ger.corp.intel.com (HELO [10.214.195.251]) ([10.214.195.251]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jan 2021 04:25:52 -0800 To: Chris Wilson , intel-gfx@lists.freedesktop.org References: <20210117110418.3361-1-chris@chris-wilson.co.uk> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: Date: Mon, 18 Jan 2021 12:25:49 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <20210117110418.3361-1-chris@chris-wilson.co.uk> Content-Language: en-US Subject: Re: [Intel-gfx] [PATCH] drm/i915/gt: Add arbitration check before semaphore wait 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: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 17/01/2021 11:04, Chris Wilson wrote: > Similar to commit 49b20dbf7497 ("drm/i915/gt: Perform an arbitration > check before busywaiting"), also add a check prior to the busywait > on gen8+, as we have now seen (because we added a selftest to add fault > injection into the engine resets) the same engine reset failure leading > to an indefinite wait on the ring-stop semaphore. So not a Tigerlake > specific bug after all, though it still seems odd behaviour for the > busywait as we do get the arbitration point elsewhere on a miss. > > Testcase: igt_reset_fail_engine > Signed-off-by: Chris Wilson > Cc: Tvrtko Ursulin > --- > drivers/gpu/drm/i915/gt/gen8_engine_cs.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c > index 5b932d2dbfd3..07ba524da90b 100644 > --- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c > +++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c > @@ -488,6 +488,7 @@ static u32 *gen8_emit_wa_tail(struct i915_request *rq, u32 *cs) > > static u32 *emit_preempt_busywait(struct i915_request *rq, u32 *cs) > { > + *cs++ = MI_ARB_CHECK; /* trigger IDLE->ACTIVE first */ > *cs++ = MI_SEMAPHORE_WAIT | > MI_SEMAPHORE_GLOBAL_GTT | > MI_SEMAPHORE_POLL | > @@ -495,6 +496,7 @@ static u32 *emit_preempt_busywait(struct i915_request *rq, u32 *cs) > *cs++ = 0; > *cs++ = preempt_address(rq->engine); > *cs++ = 0; > + *cs++ = MI_NOOP; > > return cs; > } > Reviewed-by: Tvrtko Ursulin Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx