From patchwork Wed Apr 10 14:24:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 10893923 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4349C139A for ; Wed, 10 Apr 2019 14:24:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2EB4328A4F for ; Wed, 10 Apr 2019 14:24:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2367E28AC2; Wed, 10 Apr 2019 14:24:28 +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 ADF9928A4F for ; Wed, 10 Apr 2019 14:24:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D8D718921D; Wed, 10 Apr 2019 14:24:26 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a01:7a0:2:106d:700::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id 74FA189217; Wed, 10 Apr 2019 14:24:25 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=flow.W.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1hEE9C-0002Ns-Cu; Wed, 10 Apr 2019 16:24:18 +0200 From: Sebastian Andrzej Siewior To: dri-devel@lists.freedesktop.org Date: Wed, 10 Apr 2019 16:24:13 +0200 Message-Id: <20190410142413.11873-1-bigeasy@linutronix.de> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH] drm/i915: Don't disable interrupts independently of the lock 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: , Cc: David Airlie , intel-gfx@lists.freedesktop.org, Steven Rostedt , tglx@linutronix.de, Sebastian Andrzej Siewior Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP The locks (timeline->lock and rq->lock) need to be taken with disabled interrupts. This is done in __retire_engine_request() by disabling the interrupts independently of the locks itself. While local_irq_disable()+spin_lock() equals spin_lock_irq() on vanilla it does not on RT. Also, it is not obvious if there is a special reason to why the interrupts are disabled independently of the lock. Enable/disable interrupts as part of the locking instruction. Signed-off-by: Sebastian Andrzej Siewior --- drivers/gpu/drm/i915/i915_request.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index ca95ab2f4cfa3..8744d20ac1681 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -278,9 +278,7 @@ static void __retire_engine_request(struct intel_engine_cs *engine, GEM_BUG_ON(!i915_request_completed(rq)); - local_irq_disable(); - - spin_lock(&engine->timeline.lock); + spin_lock_irq(&engine->timeline.lock); GEM_BUG_ON(!list_is_first(&rq->link, &engine->timeline.requests)); list_del_init(&rq->link); spin_unlock(&engine->timeline.lock); @@ -294,9 +292,7 @@ static void __retire_engine_request(struct intel_engine_cs *engine, GEM_BUG_ON(!atomic_read(&rq->i915->gt_pm.rps.num_waiters)); atomic_dec(&rq->i915->gt_pm.rps.num_waiters); } - spin_unlock(&rq->lock); - - local_irq_enable(); + spin_unlock_irq(&rq->lock); /* * The backing object for the context is done after switching to the