From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Widawsky Subject: [PATCH 4/4] drm/i915: optional fewer warning patch Date: Fri, 8 Apr 2011 10:47:30 -0700 Message-ID: <1302284850-8274-5-git-send-email-ben@bwidawsk.net> References: <1302284850-8274-1-git-send-email-ben@bwidawsk.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from cloud01.chad-versace.us (184-106-247-128.static.cloud-ips.com [184.106.247.128]) by gabe.freedesktop.org (Postfix) with ESMTP id E62539F304 for ; Fri, 8 Apr 2011 10:47:58 -0700 (PDT) In-Reply-To: <1302284850-8274-1-git-send-email-ben@bwidawsk.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org This patch will likely produce much fewer warnings, but perhaps hide some bugs in the driver. I believe it's a good starting point however to find the really serious issues first. Goal is to hide warnings if the refcount for the forcewake "lock" is not zero Signed-off-by: Ben Widawsky --- drivers/gpu/drm/i915/i915_drv.c | 14 ++++++++++---- 1 files changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index fcd5c9a..33341d4 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -286,9 +286,14 @@ void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv) * immediately. Not having the lock causes a race, but all bets are off * when using forced forcewake, which should only be touched through * root-only entry in debugfs. + * + * Intelligent users of the interface may do a force_wake_get() followed + * by many register reads and writes, knowing that the reference count + * is already incremented. So we do not want to warn on those. */ - WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex) && - !atomic_read(&dev_priv->forcewake_force)); + WARN_ON((!mutex_is_locked(&dev_priv->dev->struct_mutex) && + !dev_priv->forcewake_count) && + !atomic_read(&dev_priv->forcewake_force)); if (dev_priv->forcewake_count++ == 0) __gen6_gt_force_wake_get(dev_priv); @@ -302,8 +307,9 @@ static void __gen6_gt_force_wake_put(struct drm_i915_private *dev_priv) void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv) { - WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex) && - !atomic_read(&dev_priv->forcewake_force)); + WARN_ON((!mutex_is_locked(&dev_priv->dev->struct_mutex) && + !dev_priv->forcewake_count) && + !atomic_read(&dev_priv->forcewake_force)); if (--dev_priv->forcewake_count == 0) __gen6_gt_force_wake_put(dev_priv); -- 1.7.3.4