From patchwork Tue Jun 21 17:00:27 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: cpaul@redhat.com X-Patchwork-Id: 9190987 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 494996075E for ; Tue, 21 Jun 2016 17:00:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 36D71282ED for ; Tue, 21 Jun 2016 17:00:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2BA532830A; Tue, 21 Jun 2016 17:00:52 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C7CDB282ED for ; Tue, 21 Jun 2016 17:00:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 24E1F6E281; Tue, 21 Jun 2016 17:00:45 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9382C6E281; Tue, 21 Jun 2016 17:00:41 +0000 (UTC) Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 000087F6B0; Tue, 21 Jun 2016 17:00:40 +0000 (UTC) Received: from ecstaticemu.bos.redhat.com (dhcp-25-142.bos.redhat.com [10.18.25.142]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u5LH0ZSd014032; Tue, 21 Jun 2016 13:00:39 -0400 From: Lyude To: intel-gfx@lists.freedesktop.org Date: Tue, 21 Jun 2016 13:00:27 -0400 Message-Id: <1466528429-23136-4-git-send-email-cpaul@redhat.com> In-Reply-To: <1466528429-23136-1-git-send-email-cpaul@redhat.com> References: <1466528429-23136-1-git-send-email-cpaul@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 21 Jun 2016 17:00:41 +0000 (UTC) Cc: David Airlie , "open list:INTEL DRM DRIVERS excluding Poulsbo, Moorestow..., linux-kernel@vger.kernel.org open list" , stable@vger.kernel.org, Daniel Vetter Subject: [Intel-gfx] [PATCH v3 3/4] drm/i915/vlv: Disable HPD in valleyview_crt_detect_hotplug() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 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 One of the things preventing us from using polling is the fact that calling valleyview_crt_detect_hotplug() when there's a VGA cable connected results in sending another hotplug. With polling enabled when HPD is disabled, this results in a scenario like this: - We enable power wells and reset the ADPA - output_poll_exec does force probe on VGA, triggering a hpd - HPD handler waits for poll to unlock dev->mode_config.mutex - output_poll_exec shuts off the ADPA, unlocks dev->mode_config.mutex - HPD handler runs, resets ADPA and brings us back to the start This results in an endless irq storm getting sent from the ADPA whenever a VGA connector gets detected in the middle of polling. Somewhat based off of the "drm/i915: Disable CRT HPD around force trigger" patch Ville Syrjälä sent a while back Cc: stable@vger.kernel.org Cc: Ville Syrjälä Signed-off-by: Lyude --- drivers/gpu/drm/i915/i915_drv.h | 2 ++ drivers/gpu/drm/i915/intel_crt.c | 18 ++++++++++++++++++ drivers/gpu/drm/i915/intel_hotplug.c | 27 +++++++++++++++++++++++++++ 3 files changed, 47 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index a988a95..239a3ec 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2933,6 +2933,8 @@ void intel_hpd_init(struct drm_i915_private *dev_priv); void intel_hpd_init_work(struct drm_i915_private *dev_priv); void intel_hpd_cancel_work(struct drm_i915_private *dev_priv); bool intel_hpd_pin_to_port(enum hpd_pin pin, enum port *port); +bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin); +void intel_hpd_enable(struct drm_i915_private *dev_priv, enum hpd_pin pin); /* i915_irq.c */ void i915_queue_hangcheck(struct drm_i915_private *dev_priv); diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c index 220be7a..a626793 100644 --- a/drivers/gpu/drm/i915/intel_crt.c +++ b/drivers/gpu/drm/i915/intel_crt.c @@ -327,10 +327,25 @@ static bool valleyview_crt_detect_hotplug(struct drm_connector *connector) struct drm_device *dev = connector->dev; struct intel_crt *crt = intel_attached_crt(connector); struct drm_i915_private *dev_priv = dev->dev_private; + bool reenable_hpd; u32 adpa; bool ret; u32 save_adpa; + /* + * Doing a force trigger causes a hpd interrupt to get sent, which can + * get us stuck in a loop if we're polling: + * - We enable power wells and reset the ADPA + * - output_poll_exec does force probe on VGA, triggering a hpd + * - HPD handler waits for poll to unlock dev->mode_config.mutex + * - output_poll_exec shuts off the ADPA, unlocks + * dev->mode_config.mutex + * - HPD handler runs, resets ADPA and brings us back to the start + * + * Just disable HPD interrupts here to prevent this + */ + reenable_hpd = intel_hpd_disable(dev_priv, crt->base.hpd_pin); + save_adpa = adpa = I915_READ(crt->adpa_reg); DRM_DEBUG_KMS("trigger hotplug detect cycle: adpa=0x%x\n", adpa); @@ -353,6 +368,9 @@ static bool valleyview_crt_detect_hotplug(struct drm_connector *connector) DRM_DEBUG_KMS("valleyview hotplug adpa=0x%x, result %d\n", adpa, ret); + if (reenable_hpd) + intel_hpd_enable(dev_priv, crt->base.hpd_pin); + return ret; } diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c index 38eeca7..ec3285f 100644 --- a/drivers/gpu/drm/i915/intel_hotplug.c +++ b/drivers/gpu/drm/i915/intel_hotplug.c @@ -510,3 +510,30 @@ void intel_hpd_cancel_work(struct drm_i915_private *dev_priv) cancel_work_sync(&dev_priv->hotplug.hotplug_work); cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work); } + +bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin) +{ + bool ret = false; + + if (pin == HPD_NONE) + return false; + + spin_lock_irq(&dev_priv->irq_lock); + if (dev_priv->hotplug.stats[pin].state == HPD_ENABLED) { + dev_priv->hotplug.stats[pin].state = HPD_DISABLED; + ret = true; + } + spin_unlock_irq(&dev_priv->irq_lock); + + return ret; +} + +void intel_hpd_enable(struct drm_i915_private *dev_priv, enum hpd_pin pin) +{ + if (pin == HPD_NONE) + return; + + spin_lock_irq(&dev_priv->irq_lock); + dev_priv->hotplug.stats[pin].state = HPD_ENABLED; + spin_unlock_irq(&dev_priv->irq_lock); +}