[PATCH v5 8/8] drm/i915/gen9: WM memory bandwidth related workaround
Mahesh Kumar
mahesh1.kumar at intel.com
Wed Nov 23 15:28:28 UTC 2016
This patch implemnets Workariunds related to display arbitrated memory
bandwidth. These WA are applicabe for all gen-9 based platforms.
Changes since v1:
- Rebase on top of Paulo's patch series
Changes since v2:
- Address review comments
- Rebase/rework as per other patch changes in series
Signed-off-by: Mahesh Kumar <mahesh1.kumar at intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 9 +++
drivers/gpu/drm/i915/intel_pm.c | 149 +++++++++++++++++++++++++++++++++++++---
2 files changed, 149 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 171163c..f8700a6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1193,6 +1193,13 @@ enum intel_sbi_destination {
SBI_MPHY,
};
+/* SKL+ Watermark arbitrated display bandwidth Workarounds */
+enum watermark_memory_wa {
+ WATERMARK_WA_NONE,
+ WATERMARK_WA_X_TILED,
+ WATERMARK_WA_Y_TILED,
+};
+
#define QUIRK_PIPEA_FORCE (1<<0)
#define QUIRK_LVDS_SSC_DISABLE (1<<1)
#define QUIRK_INVERT_BRIGHTNESS (1<<2)
@@ -1764,6 +1771,8 @@ struct skl_ddb_allocation {
struct skl_wm_values {
unsigned dirty_pipes;
+ /* any WaterMark memory workaround Required */
+ enum watermark_memory_wa mem_wa;
struct skl_ddb_allocation ddb;
};
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 7c788ac..f42b190 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2889,11 +2889,7 @@ skl_wm_plane_id(const struct intel_plane *plane)
}
}
-/*
- * FIXME: We still don't have the proper code detect if we need to apply the WA,
- * so assume we'll always need it in order to avoid underruns.
- */
-static bool skl_needs_memory_bw_wa(struct intel_atomic_state *state)
+static bool intel_needs_memory_bw_wa(struct intel_atomic_state *state)
{
struct drm_i915_private *dev_priv = to_i915(state->base.dev);
@@ -3067,7 +3063,7 @@ bool intel_can_enable_sagv(struct drm_atomic_state *state)
latency = dev_priv->wm.skl_latency[level];
- if (skl_needs_memory_bw_wa(intel_state) &&
+ if (intel_needs_memory_bw_wa(intel_state) &&
plane->base.state->fb->modifier ==
I915_FORMAT_MOD_X_TILED)
latency += 15;
@@ -3598,7 +3594,7 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
uint32_t y_min_scanlines;
struct intel_atomic_state *state =
to_intel_atomic_state(cstate->base.state);
- bool apply_memory_bw_wa = skl_needs_memory_bw_wa(state);
+ enum watermark_memory_wa mem_wa;
bool y_tiled, x_tiled;
if (latency == 0 || !cstate->base.active || !intel_pstate->base.visible) {
@@ -3614,7 +3610,8 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
fb->modifier == I915_FORMAT_MOD_Yf_TILED;
x_tiled = fb->modifier == I915_FORMAT_MOD_X_TILED;
- if (apply_memory_bw_wa && x_tiled)
+ mem_wa = state->wm_results.mem_wa;
+ if (mem_wa != WATERMARK_WA_NONE && x_tiled)
latency += 15;
width = drm_rect_width(&intel_pstate->base.src) >> 16;
@@ -3649,7 +3646,7 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
y_min_scanlines = 4;
}
- if (apply_memory_bw_wa)
+ if (mem_wa == WATERMARK_WA_Y_TILED)
y_min_scanlines *= 2;
plane_bytes_per_line = width * cpp;
@@ -4078,6 +4075,15 @@ skl_compute_ddb(struct drm_atomic_state *state)
}
/*
+ * If Watermark workaround is changed we need to recalculate
+ * watermark values for all active pipes
+ */
+ if (intel_state->wm_results.mem_wa != dev_priv->wm.skl_hw.mem_wa) {
+ realloc_pipes = ~0;
+ intel_state->wm_results.dirty_pipes = ~0;
+ }
+
+ /*
* We're not recomputing for the pipes not included in the commit, so
* make sure we start with the current state.
*/
@@ -4103,6 +4109,129 @@ skl_compute_ddb(struct drm_atomic_state *state)
}
static void
+skl_compute_memory_bandwidth_wm_wa(struct drm_atomic_state *state)
+{
+ struct drm_device *dev = state->dev;
+ struct drm_i915_private *dev_priv = to_i915(dev);
+ struct intel_crtc *intel_crtc;
+ struct intel_plane_state *intel_pstate;
+ struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
+ struct memdev_info *memdev_info = &dev_priv->memdev_info;
+ int num_active_pipes;
+ uint32_t max_pipe_bw_kbps, total_pipe_bw_kbps;
+ int display_bw_percentage;
+ bool y_tile_enabled = false;
+
+ if (!intel_needs_memory_bw_wa(intel_state)) {
+ intel_state->wm_results.mem_wa = WATERMARK_WA_NONE;
+ return;
+ }
+
+ if (!memdev_info->valid)
+ goto exit;
+
+ max_pipe_bw_kbps = 0;
+ num_active_pipes = 0;
+ for_each_intel_crtc(dev, intel_crtc) {
+ struct intel_crtc_state *cstate;
+ struct intel_plane *plane;
+ int num_active_planes;
+ uint32_t max_plane_bw_kbps, pipe_bw_kbps;
+
+ /*
+ * If CRTC is part of current atomic commit, get crtc state from
+ * existing CRTC state. else take the cached CRTC state
+ */
+ cstate = NULL;
+ if (state)
+ cstate = intel_atomic_get_existing_crtc_state(state,
+ intel_crtc);
+ if (!cstate)
+ cstate = to_intel_crtc_state(intel_crtc->base.state);
+
+ if (!cstate->base.active)
+ continue;
+
+ num_active_planes = 0;
+ max_plane_bw_kbps = 0;
+ for_each_intel_plane_mask(dev, plane, cstate->base.plane_mask) {
+ struct drm_framebuffer *fb;
+ uint32_t plane_bw_kbps;
+ uint32_t id = skl_wm_plane_id(plane);
+
+ intel_pstate = NULL;
+ intel_pstate =
+ intel_atomic_get_existing_plane_state(state,
+ plane);
+ if (!intel_pstate)
+ intel_pstate =
+ to_intel_plane_state(plane->base.state);
+
+ if (!intel_pstate->base.visible)
+ continue;
+
+ if (WARN_ON(!intel_pstate->base.fb))
+ continue;
+
+ if (id == PLANE_CURSOR)
+ continue;
+
+ fb = intel_pstate->base.fb;
+ if ((fb->modifier == I915_FORMAT_MOD_Y_TILED ||
+ fb->modifier == I915_FORMAT_MOD_Yf_TILED))
+ y_tile_enabled = true;
+
+ plane_bw_kbps = skl_adjusted_plane_pixel_rate(cstate,
+ intel_pstate);
+ max_plane_bw_kbps = max(plane_bw_kbps,
+ max_plane_bw_kbps);
+ num_active_planes++;
+ }
+ pipe_bw_kbps = max_plane_bw_kbps * num_active_planes;
+ max_pipe_bw_kbps = max(pipe_bw_kbps, max_pipe_bw_kbps);
+ num_active_pipes++;
+ }
+
+ total_pipe_bw_kbps = max_pipe_bw_kbps * num_active_pipes;
+
+ display_bw_percentage = DIV_ROUND_UP_ULL(total_pipe_bw_kbps * 100,
+ memdev_info->bandwidth_kbps);
+
+ /*
+ * If there is any Ytile plane enabled and arbitrated display
+ * bandwidth > 20% of raw system memory bandwidth
+ * Enale Y-tile related WA
+ *
+ * If memory is dual channel single rank, Xtile limit = 35%, else Xtile
+ * limit = 60%
+ * If there is no Ytile plane enabled and
+ * arbitrated display bandwidth > Xtile limit
+ * Enable X-tile realated WA
+ */
+ if (y_tile_enabled && (display_bw_percentage > 20))
+ intel_state->wm_results.mem_wa = WATERMARK_WA_Y_TILED;
+ else {
+ int x_tile_percentage = 60;
+ enum rank rank = DRAM_RANK_SINGLE;
+
+ if (memdev_info->rank != DRAM_RANK_INVALID)
+ rank = memdev_info->rank;
+
+ if ((rank == DRAM_RANK_SINGLE) &&
+ (memdev_info->num_channels == 2))
+ x_tile_percentage = 35;
+
+ if (display_bw_percentage > x_tile_percentage)
+ intel_state->wm_results.mem_wa = WATERMARK_WA_X_TILED;
+ }
+ return;
+
+exit:
+ intel_state->wm_results.mem_wa = WATERMARK_WA_Y_TILED;
+}
+
+
+static void
skl_copy_wm_for_pipe(struct skl_wm_values *dst,
struct skl_wm_values *src,
enum pipe pipe)
@@ -4178,6 +4307,8 @@ skl_compute_wm(struct drm_atomic_state *state)
/* Clear all dirty flags */
results->dirty_pipes = 0;
+ skl_compute_memory_bandwidth_wm_wa(state);
+
ret = skl_compute_ddb(state);
if (ret)
return ret;
--
2.10.1
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