From patchwork Mon Apr 9 11:14:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10331107 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 8797A60236 for ; Mon, 9 Apr 2018 11:15:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 79F2728662 for ; Mon, 9 Apr 2018 11:15:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6EC4A28ADA; Mon, 9 Apr 2018 11:15:08 +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 1477828662 for ; Mon, 9 Apr 2018 11:15:08 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6DB046E216; Mon, 9 Apr 2018 11:15:07 +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 C4C266E1EC for ; Mon, 9 Apr 2018 11:14:59 +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 11308920-1500050 for multiple; Mon, 09 Apr 2018 12:14:49 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Mon, 09 Apr 2018 12:14:49 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Mon, 9 Apr 2018 12:14:03 +0100 Message-Id: <20180409111413.6352-9-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180409111413.6352-1-chris@chris-wilson.co.uk> References: <20180409111413.6352-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH 08/18] drm/i915: Stop parking the signaler around reset 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP We cannot call kthread_park() from softirq context, so let's avoid it entirely during the reset. We wanted to suspend the signaler so that it would not mark a request as complete at the same time as we marked it as being in error. Instead of parking the signaling, stop the engine from advancing so that the GPU doesn't emit the breadcrumb for our chosen "guilty" request. Signed-off-by: Chris Wilson Cc: Mika Kuoppala Cc: Michał Winiarski CC: Michel Thierry Cc: Jeff McGee Cc: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_gem.c | 14 -------------- drivers/gpu/drm/i915/intel_lrc.c | 21 +++++++++++++++++++++ drivers/gpu/drm/i915/intel_ringbuffer.c | 18 ++++++++++++++++++ 3 files changed, 39 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 61aca602c3a9..0a3f6a41525b 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3008,18 +3008,6 @@ i915_gem_reset_prepare_engine(struct intel_engine_cs *engine) */ intel_uncore_forcewake_get(engine->i915, FORCEWAKE_ALL); - /* - * Prevent the signaler thread from updating the request - * state (by calling dma_fence_signal) as we are processing - * the reset. The write from the GPU of the seqno is - * asynchronous and the signaler thread may see a different - * value to us and declare the request complete, even though - * the reset routine have picked that request as the active - * (incomplete) request. This conflict is not handled - * gracefully! - */ - kthread_park(engine->breadcrumbs.signaler); - request = engine->reset.prepare(engine); if (request && request->fence.error == -EIO) request = ERR_PTR(-EIO); /* Previous reset failed! */ @@ -3229,8 +3217,6 @@ void i915_gem_reset_finish_engine(struct intel_engine_cs *engine) { engine->reset.finish(engine); - kthread_unpark(engine->breadcrumbs.signaler); - intel_uncore_forcewake_put(engine->i915, FORCEWAKE_ALL); } diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index d5640f3d5276..bfafa2e4bbfc 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1764,6 +1764,21 @@ static void tasklet_kill_and_disable(struct tasklet_struct *t) smp_mb(); } +static void set_stop_engine(struct intel_engine_cs *engine) +{ + struct drm_i915_private *dev_priv = engine->i915; + const u32 base = engine->mmio_base; + const i915_reg_t mode = RING_MI_MODE(base); + + GEM_TRACE("%s\n", engine->name); + I915_WRITE_FW(mode, _MASKED_BIT_ENABLE(STOP_RING)); + if (__intel_wait_for_register_fw(dev_priv, + mode, MODE_IDLE, MODE_IDLE, + 1000, 0, + NULL)) + GEM_TRACE("%s: timed out on STOP_RING -> IDLE\n", engine->name); +} + static struct i915_request * execlists_reset_prepare(struct intel_engine_cs *engine) { @@ -1810,6 +1825,12 @@ execlists_reset_prepare(struct intel_engine_cs *engine) if (request) { unsigned long flags; + /* + * Prevent the breadcrumb from advancing before we decide + * which request is currently active. + */ + set_stop_engine(engine); + spin_lock_irqsave(&engine->timeline->lock, flags); list_for_each_entry_from_reverse(request, &engine->timeline->requests, diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 5dadbc435c0e..226c00aecd8a 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -530,8 +530,26 @@ static int init_ring_common(struct intel_engine_cs *engine) return ret; } +static void set_stop_engine(struct intel_engine_cs *engine) +{ + struct drm_i915_private *dev_priv = engine->i915; + const u32 base = engine->mmio_base; + const i915_reg_t mode = RING_MI_MODE(base); + + I915_WRITE_FW(mode, _MASKED_BIT_ENABLE(STOP_RING)); + if (__intel_wait_for_register_fw(dev_priv, + mode, MODE_IDLE, MODE_IDLE, + 1000, 0, + NULL)) + DRM_DEBUG_DRIVER("%s: timed out on STOP_RING\n", + engine->name); +} + static struct i915_request *reset_prepare(struct intel_engine_cs *engine) { + if (INTEL_GEN(engine->i915) >= 3) + set_stop_engine(engine); + if (engine->irq_seqno_barrier) engine->irq_seqno_barrier(engine);