From patchwork Wed May 9 14:27:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10389681 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0115060236 for ; Wed, 9 May 2018 14:28:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 888D428671 for ; Wed, 9 May 2018 14:28:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7D3B42869F; Wed, 9 May 2018 14:28:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 0E59D28674 for ; Wed, 9 May 2018 14:28:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F3FF96ED2D; Wed, 9 May 2018 14:28:14 +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 34D6A6ED28 for ; Wed, 9 May 2018 14:28:12 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 11646609-1500050 for multiple; Wed, 09 May 2018 15:28:01 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Wed, 09 May 2018 15:28:02 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 9 May 2018 15:27:57 +0100 Message-Id: <20180509142801.28130-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.17.0 X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH 1/5] drm/i915: Remove tasklet flush before disable X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP The idea was to try and let the existing tasklet run to completion before we began the reset, but it involves a racy check against anything else that tries to run the tasklet. Rather than acknowledge and ignore the race, let it be and don't try and be too clever. The tasklet will resume execution after reset (after spinning a bit during reset), but before we allow it to resume we will have cleared all the pending state. Signed-off-by: Chris Wilson Cc: Mika Kuoppala --- drivers/gpu/drm/i915/i915_gem.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 89bf5d67cb74..63c96c2b8fcf 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3035,16 +3035,7 @@ i915_gem_reset_prepare_engine(struct intel_engine_cs *engine) * calling engine->init_hw() and also writing the ELSP. * Turning off the execlists->tasklet until the reset is over * prevents the race. - * - * Note that this needs to be a single atomic operation on the - * tasklet (flush existing tasks, prevent new tasks) to prevent - * a race between reset and set-wedged. It is not, so we do the best - * we can atm and make sure we don't lock the machine up in the more - * common case of recursively being called from set-wedged from inside - * i915_reset. */ - if (!atomic_read(&engine->execlists.tasklet.count)) - tasklet_kill(&engine->execlists.tasklet); tasklet_disable(&engine->execlists.tasklet); /*