From patchwork Tue Apr 12 20:31:40 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 701971 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p3CKdlC8002259 for ; Tue, 12 Apr 2011 20:40:08 GMT Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E0E279EF86 for ; Tue, 12 Apr 2011 13:39:47 -0700 (PDT) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTP id 6DDFA9EF75 for ; Tue, 12 Apr 2011 13:32:33 -0700 (PDT) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP; 12 Apr 2011 13:32:33 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.64,199,1301900400"; d="scan'208";a="627581918" Received: from unknown (HELO cantiga.alporthouse.com) ([10.255.16.172]) by orsmga002.jf.intel.com with ESMTP; 12 Apr 2011 13:32:31 -0700 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Tue, 12 Apr 2011 21:31:40 +0100 Message-Id: <1302640318-23165-13-git-send-email-chris@chris-wilson.co.uk> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1302640318-23165-1-git-send-email-chris@chris-wilson.co.uk> References: <1302640318-23165-1-git-send-email-chris@chris-wilson.co.uk> Subject: [Intel-gfx] [PATCH 12/30] drm/i915: fix rc6 initialization on Ironlake X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: intel-gfx-bounces+patchwork-intel-gfx=patchwork.kernel.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+patchwork-intel-gfx=patchwork.kernel.org@lists.freedesktop.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Tue, 12 Apr 2011 20:40:08 +0000 (UTC) From: Ben Widawsky There is a race condition between setting PWRCTXA and executing MI_SET_CONTEXT. PWRCTXA must not be set until a valid context has been written (or else the GPU could possible go into rc6, and return to an invalid context). Reported-and-Tested-by: Gu Rui Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=28582 Signed-off-by: Ben Widawsky Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/intel_display.c | 16 +++++++++++++--- 1 files changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index bebb8e8..d386065 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -7174,9 +7174,6 @@ void ironlake_enable_rc6(struct drm_device *dev) struct drm_i915_private *dev_priv = dev->dev_private; int ret; - /* rc6 disabled by default due to repeated reports of hanging during - * boot and resume. - */ if (!i915_enable_rc6) return; @@ -7210,6 +7207,19 @@ void ironlake_enable_rc6(struct drm_device *dev) OUT_RING(MI_FLUSH); ADVANCE_LP_RING(); + /* + * Wait for the command parser to advance past MI_SET_CONTEXT. The HW + * does an implicit flush, combined with MI_FLUSH above, it should be + * safe to assume that renderctx is valid + */ + ret = intel_wait_ring_idle(LP_RING(dev_priv)); + if (ret) { + DRM_ERROR("failed to enable ironlake power power savings\n"); + ironlake_teardown_rc6(dev); + mutex_unlock(&dev->struct_mutex); + return; + } + I915_WRITE(PWRCTXA, dev_priv->pwrctx->gtt_offset | PWRCTX_EN); I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) & ~RCX_SW_EXIT); mutex_unlock(&dev->struct_mutex);