From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: [PATCH] drm/i915: implement WaIssueDummyWriteToWakeupFromRC6 Date: Thu, 18 Oct 2012 14:16:09 +0200 Message-ID: <1350562569-5879-1-git-send-email-daniel.vetter@ffwll.ch> References: <275ffc$71to91@fmsmga002.fm.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wi0-f177.google.com (mail-wi0-f177.google.com [209.85.212.177]) by gabe.freedesktop.org (Postfix) with ESMTP id 6CCCF9E815 for ; Thu, 18 Oct 2012 04:58:18 -0700 (PDT) Received: by mail-wi0-f177.google.com with SMTP id hj13so1436952wib.12 for ; Thu, 18 Oct 2012 04:58:17 -0700 (PDT) In-Reply-To: <275ffc$71to91@fmsmga002.fm.intel.com> 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 Graphics Development Cc: Daniel Vetter List-Id: intel-gfx@lists.freedesktop.org Or at least our best understanding of it. v2: Fixup commit message and put the wa name into the comment block. And actually update the commit, too. Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_drv.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index a7837e5..fb6b633 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -1131,9 +1131,20 @@ static bool IS_DISPLAYREG(u32 reg) return true; } +static void +ilk_dummy_write(struct drm_i915_private *dev_priv) +{ + /* WaIssueDummyWriteToWakeupFromRC6: Issue a dummy write to wake up the + * chip from rc6 before touching it for real. MI_MODE is masked, hence + * harmless to write 0 into. */ + I915_WRITE_NOTRACE(MI_MODE, 0); +} + #define __i915_read(x, y) \ u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg) { \ u##x val = 0; \ + if (IS_GEN5(dev_priv->dev)) \ + ilk_dummy_write(dev_priv); \ if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \ unsigned long irqflags; \ spin_lock_irqsave(&dev_priv->gt_lock, irqflags); \ @@ -1165,6 +1176,8 @@ void i915_write##x(struct drm_i915_private *dev_priv, u32 reg, u##x val) { \ if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \ __fifo_ret = __gen6_gt_wait_for_fifo(dev_priv); \ } \ + if (IS_GEN5(dev_priv->dev)) \ + ilk_dummy_write(dev_priv); \ if (IS_VALLEYVIEW(dev_priv->dev) && IS_DISPLAYREG(reg)) { \ write##y(val, dev_priv->regs + reg + 0x180000); \ } else { \ -- 1.7.10.4