From 8a6c5447635c4039eb51801fb5dcdb8c7ef93cfb Mon Sep 17 00:00:00 2001 From: Mahesh Kumar Date: Fri, 24 Aug 2018 15:02:25 +0530 Subject: [PATCH] drm/i915/kbl+: Enable IPC only for symmetric memory configurations IPC may cause underflows if not used with dual channel symmetric memory configuration. Disable IPC for non symmetric configurations in affected platforms. Display WA #1141 Changes Since V1: - Re-arrange the code. - update wrapper to return if memory is symmetric (Rodrigo) Signed-off-by: Mahesh Kumar Reviewed-by: Maarten Lankhorst Signed-off-by: Rodrigo Vivi Link: https://patchwork.freedesktop.org/patch/msgid/20180824093225.12598-6-mahesh1.kumar@intel.com --- drivers/gpu/drm/i915/i915_drv.c | 27 ++++++++++++++++++++++----- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/intel_pm.c | 5 +++++ 3 files changed, 28 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index c293341a6ad6..dbe40b21fef8 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -1141,21 +1141,32 @@ skl_dram_get_channel_info(struct dram_channel_info *ch, u32 val) return 0; } +static bool +intel_is_dram_symmetric(u32 val_ch0, u32 val_ch1, + struct dram_channel_info *ch0) +{ + return (val_ch0 == val_ch1 && + (ch0->s_info.size == 0 || + (ch0->l_info.size == ch0->s_info.size && + ch0->l_info.width == ch0->s_info.width && + ch0->l_info.rank == ch0->s_info.rank))); +} + static int skl_dram_get_channels_info(struct drm_i915_private *dev_priv) { struct dram_info *dram_info = &dev_priv->dram_info; struct dram_channel_info ch0, ch1; - u32 val; + u32 val_ch0, val_ch1; int ret; - val = I915_READ(SKL_MAD_DIMM_CH0_0_0_0_MCHBAR_MCMAIN); - ret = skl_dram_get_channel_info(&ch0, val); + val_ch0 = I915_READ(SKL_MAD_DIMM_CH0_0_0_0_MCHBAR_MCMAIN); + ret = skl_dram_get_channel_info(&ch0, val_ch0); if (ret == 0) dram_info->num_channels++; - val = I915_READ(SKL_MAD_DIMM_CH1_0_0_0_MCHBAR_MCMAIN); - ret = skl_dram_get_channel_info(&ch1, val); + val_ch1 = I915_READ(SKL_MAD_DIMM_CH1_0_0_0_MCHBAR_MCMAIN); + ret = skl_dram_get_channel_info(&ch1, val_ch1); if (ret == 0) dram_info->num_channels++; @@ -1185,6 +1196,12 @@ skl_dram_get_channels_info(struct drm_i915_private *dev_priv) if (ch0.is_16gb_dimm || ch1.is_16gb_dimm) dram_info->is_16gb_dimm = true; + dev_priv->dram_info.symmetric_memory = intel_is_dram_symmetric(val_ch0, + val_ch1, + &ch0); + + DRM_DEBUG_KMS("memory configuration is %sSymmetric memory\n", + dev_priv->dram_info.symmetric_memory ? "" : "not "); return 0; } diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 89366c20196a..ea6c6f715ca6 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1956,6 +1956,7 @@ struct drm_i915_private { I915_DRAM_RANK_DUAL } rank; u32 bandwidth_kbps; + bool symmetric_memory; } dram_info; struct i915_runtime_pm runtime_pm; diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index ac8177032faf..1db9b8328275 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -6121,6 +6121,11 @@ void intel_enable_ipc(struct drm_i915_private *dev_priv) if (IS_SKYLAKE(dev_priv)) dev_priv->ipc_enabled = false; + /* Display WA #1141: SKL:all KBL:all CFL */ + if ((IS_KABYLAKE(dev_priv) || IS_COFFEELAKE(dev_priv)) && + !dev_priv->dram_info.symmetric_memory) + dev_priv->ipc_enabled = false; + val = I915_READ(DISP_ARB_CTL2); if (dev_priv->ipc_enabled)