From patchwork Fri Mar 22 18:08:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= X-Patchwork-Id: 10866403 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 5F86C14DE for ; Fri, 22 Mar 2019 18:08:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 474FC2A97E for ; Fri, 22 Mar 2019 18:08:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3BD912A981; Fri, 22 Mar 2019 18:08:09 +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 8A3282A97E for ; Fri, 22 Mar 2019 18:08:08 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0E39A6E232; Fri, 22 Mar 2019 18:08:08 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id 37EAB6E232 for ; Fri, 22 Mar 2019 18:08:07 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Mar 2019 11:08:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,256,1549958400"; d="scan'208";a="133895559" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by fmsmga008.fm.intel.com with SMTP; 22 Mar 2019 11:08:04 -0700 Received: by stinkbox (sSMTP sendmail emulation); Fri, 22 Mar 2019 20:08:04 +0200 From: Ville Syrjala To: intel-gfx@lists.freedesktop.org Date: Fri, 22 Mar 2019 20:08:03 +0200 Message-Id: <20190322180804.3300-1-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.19.2 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 1/2] drm/i915: Disable C3 when enabling vblank interrupts on i945gm 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 From: Ville Syrjälä The AGPBUSY thing doesn't work on i945gm anymore. This means the gmch is incapable of waking the CPU from C3 when an interrupt is generated. The interrupts just get postponed indefinitely until something wakes up the CPU. This is rather annoying for vblank interrupts as we are unable to maintain a steady framerate unless the machine is sufficiently loaded to stay out of C3. To combat this let's use pm_qos to prevent C3 whenever vblank interrupts are enabled. To maintain reasonable amount of powersaving we will attempt to limit this to C3 only while leaving C1 and C2 enabled. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=30364 Signed-off-by: Ville Syrjälä Reviewed-by: Chris Wilson --- drivers/gpu/drm/i915/i915_drv.h | 8 +++ drivers/gpu/drm/i915/i915_irq.c | 88 +++++++++++++++++++++++++++++++++ 2 files changed, 96 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index f723b15527f8..0c736f8ca1b2 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2042,6 +2042,14 @@ struct drm_i915_private { struct i915_vma *scratch; } gt; + /* For i945gm vblank irq vs. C3 workaround */ + struct { + struct work_struct work; + struct pm_qos_request pm_qos; + u8 c3_disable_latency; + u8 enabled; + } i945gm_vblank; + /* perform PHY state sanity checks? */ bool chv_phy_assert[2]; diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 2f788291cfe0..33386f0acab3 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -30,6 +30,7 @@ #include #include +#include #include #include #include @@ -3131,6 +3132,16 @@ static int i8xx_enable_vblank(struct drm_device *dev, unsigned int pipe) return 0; } +static int i945gm_enable_vblank(struct drm_device *dev, unsigned int pipe) +{ + struct drm_i915_private *dev_priv = to_i915(dev); + + if (dev_priv->i945gm_vblank.enabled++ == 0) + schedule_work(&dev_priv->i945gm_vblank.work); + + return i8xx_enable_vblank(dev, pipe); +} + static int i965_enable_vblank(struct drm_device *dev, unsigned int pipe) { struct drm_i915_private *dev_priv = to_i915(dev); @@ -3195,6 +3206,16 @@ static void i8xx_disable_vblank(struct drm_device *dev, unsigned int pipe) spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags); } +static void i945gm_disable_vblank(struct drm_device *dev, unsigned int pipe) +{ + struct drm_i915_private *dev_priv = to_i915(dev); + + i8xx_disable_vblank(dev, pipe); + + if (--dev_priv->i945gm_vblank.enabled == 0) + schedule_work(&dev_priv->i945gm_vblank.work); +} + static void i965_disable_vblank(struct drm_device *dev, unsigned int pipe) { struct drm_i915_private *dev_priv = to_i915(dev); @@ -3228,6 +3249,60 @@ static void gen8_disable_vblank(struct drm_device *dev, unsigned int pipe) spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags); } +static void i945gm_vblank_work_func(struct work_struct *work) +{ + struct drm_i915_private *dev_priv = + container_of(work, struct drm_i915_private, i945gm_vblank.work); + + /* + * Vblank interrupts fail to wake up the device from C3, + * hence we want to prevent C3 usage while vblank interrupts + * are enabled. + */ + pm_qos_update_request(&dev_priv->i945gm_vblank.pm_qos, + dev_priv->i945gm_vblank.enabled ? + dev_priv->i945gm_vblank.c3_disable_latency : + PM_QOS_DEFAULT_VALUE); +} + +static int cstate_disable_latency(const char *name) +{ + const struct cpuidle_driver *drv; + int i; + + drv = cpuidle_get_driver(); + if (!drv) + return 0; + + for (i = 0; i < drv->state_count; i++) { + const struct cpuidle_state *state = &drv->states[i]; + + if (!strcmp(state->name, name)) + return state->exit_latency ? + state->exit_latency - 1 : 0; + } + + return 0; +} + +static void i945gm_vblank_work_init(struct drm_i915_private *dev_priv) +{ + INIT_WORK(&dev_priv->i945gm_vblank.work, + i945gm_vblank_work_func); + + dev_priv->i945gm_vblank.c3_disable_latency = + cstate_disable_latency("C3"); + pm_qos_add_request(&dev_priv->i945gm_vblank.pm_qos, + PM_QOS_CPU_DMA_LATENCY, + PM_QOS_DEFAULT_VALUE); +} + +static void i945gm_vblank_work_fini(struct drm_i915_private *dev_priv) +{ + cancel_work_sync(&dev_priv->i945gm_vblank.work); + pm_qos_remove_request(&dev_priv->i945gm_vblank.pm_qos); +} + static void ibx_irq_reset(struct drm_i915_private *dev_priv) { if (HAS_PCH_NOP(dev_priv)) @@ -4525,6 +4600,9 @@ void intel_irq_init(struct drm_i915_private *dev_priv) struct intel_rps *rps = &dev_priv->gt_pm.rps; int i; + if (IS_I945GM(dev_priv)) + i945gm_vblank_work_init(dev_priv); + intel_hpd_init_work(dev_priv); INIT_WORK(&rps->work, gen6_pm_rps_work); @@ -4647,6 +4725,13 @@ void intel_irq_init(struct drm_i915_private *dev_priv) dev->driver->irq_uninstall = i8xx_irq_reset; dev->driver->enable_vblank = i8xx_enable_vblank; dev->driver->disable_vblank = i8xx_disable_vblank; + } else if (IS_I945GM(dev_priv)) { + dev->driver->irq_preinstall = i915_irq_reset; + dev->driver->irq_postinstall = i915_irq_postinstall; + dev->driver->irq_uninstall = i915_irq_reset; + dev->driver->irq_handler = i915_irq_handler; + dev->driver->enable_vblank = i945gm_enable_vblank; + dev->driver->disable_vblank = i945gm_disable_vblank; } else if (IS_GEN(dev_priv, 3)) { dev->driver->irq_preinstall = i915_irq_reset; dev->driver->irq_postinstall = i915_irq_postinstall; @@ -4677,6 +4762,9 @@ void intel_irq_fini(struct drm_i915_private *i915) { int i; + if (IS_I945GM(i915)) + i945gm_vblank_work_fini(i915); + for (i = 0; i < MAX_L3_SLICES; ++i) kfree(i915->l3_parity.remap_info[i]); }