From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: [PATCH 5/5] drm/i915/gmbus: Reset the controller on initialisation Date: Tue, 5 Apr 2011 10:24:18 +0100 Message-ID: <1301995458-2699-6-git-send-email-chris@chris-wilson.co.uk> References: <1301995458-2699-1-git-send-email-chris@chris-wilson.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from fireflyinternet.com (server109-228-6-236.live-servers.net [109.228.6.236]) by gabe.freedesktop.org (Postfix) with ESMTP id BEF599E812 for ; Tue, 5 Apr 2011 02:24:25 -0700 (PDT) In-Reply-To: <1301995458-2699-1-git-send-email-chris@chris-wilson.co.uk> 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 Toggle the Software Clear Interrupt bit which resets the controller to clear any prior BUS_ERROR condition before we begin to use the controller in earnest. Suggested-by: Ben Widawsky Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/intel_i2c.c | 14 +++++++++++--- 1 files changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index d3b903b..f9f0c42 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -55,10 +55,18 @@ void intel_i2c_reset(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; + int reg_offset; + + reg_offset = 0; if (HAS_PCH_SPLIT(dev)) - I915_WRITE(PCH_GMBUS0, 0); - else - I915_WRITE(GMBUS0, 0); + reg_offset = PCH_GMBUS0 - GMBUS0; + + /* First reset the controller by toggling the Sw Clear Interrupt. */ + I915_WRITE(GMBUS1 + reg_offset, GMBUS_SW_CLR_INT); + I915_WRITE(GMBUS1 + reg_offset, 0); + + /* Then mark the controller as disabled. */ + I915_WRITE(GMBUS0 + reg_offset, 0); } static void intel_i2c_quirk_set(struct drm_i915_private *dev_priv, bool enable) -- 1.7.4.1