From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesse Barnes Subject: Re: [PATCH] drm/i915: Revert workaround for disabling L3 cache aging on BYT Date: Thu, 20 Feb 2014 08:18:39 -0800 Message-ID: <20140220081839.2e75142d@jbarnes-desktop> References: <1392416009-27050-1-git-send-email-sinclair.yeh@intel.com> <1392844171-14645-1-git-send-email-sinclair.yeh@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from oproxy17-pub.mail.unifiedlayer.com (oproxy17-pub.mail.unifiedlayer.com [74.220.201.171]) by gabe.freedesktop.org (Postfix) with SMTP id 44546FA6D7 for ; Thu, 20 Feb 2014 08:25:06 -0800 (PST) In-Reply-To: <1392844171-14645-1-git-send-email-sinclair.yeh@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org To: Sinclair Yeh Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Wed, 19 Feb 2014 13:09:31 -0800 Sinclair Yeh wrote: > V2: edit the commit message to contain more info > The W/A spreadsheet says this is still required, but the b-spec says > it's not for BYT-T. So the documentation is not clear. However, > our experience with the other SKUs of BYT-I/M on Android and Linux > suggests that setting this bit actually causes GPU hang for certain > OGL benchmark applications. > > Removing this bit completely resolves the GPU hangs. > --- > drivers/gpu/drm/i915/intel_pm.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > index a6b877a..3ba037e 100644 > --- a/drivers/gpu/drm/i915/intel_pm.c > +++ b/drivers/gpu/drm/i915/intel_pm.c > @@ -5004,9 +5004,6 @@ static void valleyview_init_clock_gating(struct drm_device *dev) > _MASKED_BIT_ENABLE(GEN7_MAX_PS_THREAD_DEP | > GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE)); > > - /* WaDisableL3CacheAging:vlv */ > - I915_WRITE(GEN7_L3CNTLREG1, I915_READ(GEN7_L3CNTLREG1) | GEN7_L3AGDIS); > - > /* WaForceL3Serialization:vlv */ > I915_WRITE(GEN7_L3SQCREG4, I915_READ(GEN7_L3SQCREG4) & > ~L3SQ_URB_READ_CAM_MATCH_DISABLE); I don't think we have good docs on this, but since it works empirically: Acked-by: Jesse Barnes -- Jesse Barnes, Intel Open Source Technology Center