From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Widawsky Subject: [PATCH 1/2] [v2] drm/i915/bdw: Force all Data Cache Data Port access to be Non-Coherent Date: Thu, 12 Dec 2013 17:26:03 -0800 Message-ID: <1386897963-28188-1-git-send-email-benjamin.widawsky@intel.com> References: <1386897407.18488.56.camel@xhh-ivb32> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTP id A9B33FA5BD for ; Thu, 12 Dec 2013 17:26:04 -0800 (PST) In-Reply-To: <1386897407.18488.56.camel@xhh-ivb32> 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 Cc: Ben Widawsky , Ben Widawsky List-Id: intel-gfx@lists.freedesktop.org I stumbled on to some unimplemented errata. To be honest, I am not really sure of the impact, just that the docs say to do. No w/a name for this one. v2: v1 was a stale thing which should have never seen the light of day. (Haihao) Cc: Kenneth Graunke Signed-off-by: Ben Widawsky --- drivers/gpu/drm/i915/i915_reg.h | 4 ++++ drivers/gpu/drm/i915/intel_pm.c | 8 ++++++++ 2 files changed, 12 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index e8cc27c..3259e83 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -4167,6 +4167,10 @@ #define GEN7_L3SQCREG4 0xb034 #define L3SQ_URB_READ_CAM_MATCH_DISABLE (1<<27) +/* GEN8 chicken */ +#define HDC_CHICKEN0 0x7300 +#define HDC_FORCE_NON_COHERENT (1<<4) + /* WaCatErrorRejectionIssue */ #define GEN7_SQ_CHICKEN_MBCUNIT_CONFIG 0x9030 #define GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB (1<<11) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index ac9dd46..0665e37 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -5279,6 +5279,14 @@ static void gen8_init_clock_gating(struct drm_device *dev) I915_READ(CHICKEN_PIPESL_1(i) | DPRS_MASK_VBLANK_SRD)); } + + /* Use Force Non-Coherent whenever executing a 3D context. This is a + * workaround for for a possible hang in the unlikely event a TLB + * invalidation occurs during a PSD flush. + */ + I915_WRITE(HDC_CHICKEN0, + I915_READ(HDC_CHICKEN0) | + _MASKED_BIT_ENABLE(HDC_FORCE_NON_COHERENT)); } static void haswell_init_clock_gating(struct drm_device *dev) -- 1.8.4.2