From 86b592876cb6b277e5cb3c988fc5f748fdafa16f Mon Sep 17 00:00:00 2001 From: Mahesh Kumar Date: Fri, 31 Aug 2018 16:39:42 +0530 Subject: [PATCH] drm/i915: Implement 16GB dimm wa for latency level-0 Memory with 16GB dimms require an increase of 1us in level-0 latency. This patch implements the same. Bspec: 4381 changes since V1: - s/memdev_info/dram_info - make skl_is_16gb_dimm pure function Changes since V2: - make is_16gb_dimm more generic - rebase Changes since V3: - Simplify condition (Maarten) Signed-off-by: Mahesh Kumar Reviewed-by: Maarten Lankhorst Signed-off-by: Rodrigo Vivi Link: https://patchwork.freedesktop.org/patch/msgid/20180831110942.9234-1-mahesh1.kumar@intel.com --- drivers/gpu/drm/i915/i915_drv.c | 33 +++++++++++++++++++++++++++++++-- drivers/gpu/drm/i915/i915_drv.h | 3 +++ drivers/gpu/drm/i915/intel_pm.c | 10 ++++++++++ 3 files changed, 44 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 361dfcd44fe8..c293341a6ad6 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -1075,6 +1075,21 @@ static enum dram_rank skl_get_dimm_rank(u8 size, u32 rank) return I915_DRAM_RANK_INVALID; } +static bool +skl_is_16gb_dimm(enum dram_rank rank, u8 size, u8 width) +{ + if (rank == I915_DRAM_RANK_SINGLE && width == 8 && size == 16) + return true; + else if (rank == I915_DRAM_RANK_DUAL && width == 8 && size == 32) + return true; + else if (rank == SKL_DRAM_RANK_SINGLE && width == 16 && size == 8) + return true; + else if (rank == SKL_DRAM_RANK_DUAL && width == 16 && size == 16) + return true; + + return false; +} + static int skl_dram_get_channel_info(struct dram_channel_info *ch, u32 val) { @@ -1112,6 +1127,11 @@ skl_dram_get_channel_info(struct dram_channel_info *ch, u32 val) else ch->rank = I915_DRAM_RANK_SINGLE; + ch->is_16gb_dimm = skl_is_16gb_dimm(ch->l_info.rank, ch->l_info.size, + ch->l_info.width) || + skl_is_16gb_dimm(ch->s_info.rank, ch->s_info.size, + ch->s_info.width); + DRM_DEBUG_KMS("(size:width:rank) L(%dGB:X%d:%s) S(%dGB:X%d:%s)\n", ch->l_info.size, ch->l_info.width, ch->l_info.rank ? "dual" : "single", @@ -1144,6 +1164,8 @@ skl_dram_get_channels_info(struct drm_i915_private *dev_priv) return -EINVAL; } + dram_info->valid_dimm = true; + /* * If any of the channel is single rank channel, worst case output * will be same as if single rank memory, so consider single rank @@ -1159,6 +1181,10 @@ skl_dram_get_channels_info(struct drm_i915_private *dev_priv) DRM_INFO("couldn't get memory rank information\n"); return -EINVAL; } + + if (ch0.is_16gb_dimm || ch1.is_16gb_dimm) + dram_info->is_16gb_dimm = true; + return 0; } @@ -1271,6 +1297,7 @@ bxt_get_dram_info(struct drm_i915_private *dev_priv) return -EINVAL; } + dram_info->valid_dimm = true; dram_info->valid = true; return 0; } @@ -1283,6 +1310,8 @@ intel_get_dram_info(struct drm_i915_private *dev_priv) int ret; dram_info->valid = false; + dram_info->valid_dimm = false; + dram_info->is_16gb_dimm = false; dram_info->rank = I915_DRAM_RANK_INVALID; dram_info->bandwidth_kbps = 0; dram_info->num_channels = 0; @@ -1306,9 +1335,9 @@ intel_get_dram_info(struct drm_i915_private *dev_priv) sprintf(bandwidth_str, "unknown"); DRM_DEBUG_KMS("DRAM bandwidth:%s, total-channels: %u\n", bandwidth_str, dram_info->num_channels); - DRM_DEBUG_KMS("DRAM rank: %s rank\n", + DRM_DEBUG_KMS("DRAM rank: %s rank 16GB-dimm:%s\n", (dram_info->rank == I915_DRAM_RANK_DUAL) ? - "dual" : "single"); + "dual" : "single", yesno(dram_info->is_16gb_dimm)); } /** diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index e7eb04b01b08..89366c20196a 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1947,6 +1947,8 @@ struct drm_i915_private { struct dram_info { bool valid; + bool valid_dimm; + bool is_16gb_dimm; u8 num_channels; enum dram_rank { I915_DRAM_RANK_INVALID = 0, @@ -2175,6 +2177,7 @@ struct dram_channel_info { enum dram_rank rank; } l_info, s_info; enum dram_rank rank; + bool is_16gb_dimm; }; static inline struct drm_i915_private *to_i915(const struct drm_device *dev) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index d99e5fabe93c..09463e3d7948 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -2875,6 +2875,16 @@ static void intel_read_wm_latency(struct drm_i915_private *dev_priv, } } + /* + * WA Level-0 adjustment for 16GB DIMMs: SKL+ + * If we could not get dimm info enable this WA to prevent from + * any underrun. If not able to get Dimm info assume 16GB dimm + * to avoid any underrun. + */ + if (!dev_priv->dram_info.valid_dimm || + dev_priv->dram_info.is_16gb_dimm) + wm[0] += 1; + } else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) { uint64_t sskpd = I915_READ64(MCH_SSKPD); -- GitLab