drm/i915: Include TLB miss latency in g4x watermark computations
Reports of FIFO underruns are still persisting on gm45.
References: https://bugs.freedesktop.org/show_bug.cgi?id=27589
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2f58d97..2c2ecab 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3604,89 +3604,177 @@
}
}
-static void g4x_update_wm(struct drm_device *dev, int planea_clock,
- int planeb_clock, int sr_hdisplay, int sr_htotal,
- int pixel_size)
+static bool g4x_compute_wm0(struct drm_device *dev,
+ int plane,
+ const struct intel_watermark_params *display,
+ int display_latency_ns,
+ const struct intel_watermark_params *cursor,
+ int cursor_latency_ns,
+ int *plane_wm,
+ int *cursor_wm)
{
- struct drm_i915_private *dev_priv = dev->dev_private;
- int total_size, cacheline_size;
- int planea_wm, planeb_wm, cursora_wm, cursorb_wm, cursor_sr;
- struct intel_watermark_params planea_params, planeb_params;
- unsigned long line_time_us;
- int sr_clock, sr_entries = 0, entries_required;
+ struct drm_crtc *crtc;
+ int htotal, hdisplay, clock, pixel_size;
+ int line_time_us, line_count;
+ int entries, tlb_miss;
- /* Create copies of the base settings for each pipe */
- planea_params = planeb_params = g4x_wm_info;
+ crtc = intel_get_crtc_for_plane(dev, plane);
+ if (crtc->fb == NULL || !crtc->enabled)
+ return false;
- /* Grab a couple of global values before we overwrite them */
- total_size = planea_params.fifo_size;
- cacheline_size = planea_params.cacheline_size;
+ htotal = crtc->mode.htotal;
+ hdisplay = crtc->mode.hdisplay;
+ clock = crtc->mode.clock;
+ pixel_size = crtc->fb->bits_per_pixel / 8;
- /*
- * Note: we need to make sure we don't overflow for various clock &
- * latency values.
- * clocks go from a few thousand to several hundred thousand.
- * latency is usually a few thousand
- */
- entries_required = ((planea_clock / 1000) * pixel_size * latency_ns) /
- 1000;
- entries_required = DIV_ROUND_UP(entries_required, G4X_FIFO_LINE_SIZE);
- planea_wm = entries_required + planea_params.guard_size;
+ /* Use the small buffer method to calculate plane watermark */
+ entries = ((clock * pixel_size / 1000) * display_latency_ns) / 1000;
+ tlb_miss = display->fifo_size*display->cacheline_size - hdisplay * 8;
+ if (tlb_miss > 0)
+ entries += tlb_miss;
+ entries = DIV_ROUND_UP(entries, display->cacheline_size);
+ *plane_wm = entries + display->guard_size;
+ if (*plane_wm > (int)display->max_wm)
+ *plane_wm = display->max_wm;
- entries_required = ((planeb_clock / 1000) * pixel_size * latency_ns) /
- 1000;
- entries_required = DIV_ROUND_UP(entries_required, G4X_FIFO_LINE_SIZE);
- planeb_wm = entries_required + planeb_params.guard_size;
+ /* Use the large buffer method to calculate cursor watermark */
+ line_time_us = ((htotal * 1000) / clock);
+ line_count = (cursor_latency_ns / line_time_us + 1000) / 1000;
+ entries = line_count * 64 * pixel_size;
+ tlb_miss = cursor->fifo_size*cursor->cacheline_size - hdisplay * 8;
+ if (tlb_miss > 0)
+ entries += tlb_miss;
+ entries = DIV_ROUND_UP(entries, cursor->cacheline_size);
+ *cursor_wm = entries + cursor->guard_size;
+ if (*cursor_wm > (int)cursor->max_wm)
+ *cursor_wm = (int)cursor->max_wm;
- cursora_wm = cursorb_wm = 16;
- cursor_sr = 32;
+ return true;
+}
- DRM_DEBUG("FIFO watermarks - A: %d, B: %d\n", planea_wm, planeb_wm);
+/*
+ * Check the wm result.
+ *
+ * If any calculated watermark values is larger than the maximum value that
+ * can be programmed into the associated watermark register, that watermark
+ * must be disabled.
+ */
+static bool g4x_check_srwm(struct drm_device *dev,
+ int display_wm, int cursor_wm,
+ const struct intel_watermark_params *display,
+ const struct intel_watermark_params *cursor)
+{
+ DRM_DEBUG_KMS("SR watermark: display plane %d, cursor %d\n",
+ display_wm, cursor_wm);
- /* Calc sr entries for one plane configs */
- if (sr_hdisplay && (!planea_clock || !planeb_clock)) {
- /* self-refresh has much higher latency */
- static const int sr_latency_ns = 12000;
-
- sr_clock = planea_clock ? planea_clock : planeb_clock;
- line_time_us = ((sr_htotal * 1000) / sr_clock);
-
- /* Use ns/us then divide to preserve precision */
- sr_entries = (((sr_latency_ns / line_time_us) + 1000) / 1000) *
- pixel_size * sr_hdisplay;
- sr_entries = DIV_ROUND_UP(sr_entries, cacheline_size);
-
- entries_required = (((sr_latency_ns / line_time_us) +
- 1000) / 1000) * pixel_size * 64;
- entries_required = DIV_ROUND_UP(entries_required,
- g4x_cursor_wm_info.cacheline_size);
- cursor_sr = entries_required + g4x_cursor_wm_info.guard_size;
-
- if (cursor_sr > g4x_cursor_wm_info.max_wm)
- cursor_sr = g4x_cursor_wm_info.max_wm;
- DRM_DEBUG_KMS("self-refresh watermark: display plane %d "
- "cursor %d\n", sr_entries, cursor_sr);
-
- I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN);
- } else {
- /* Turn off self refresh if both pipes are enabled */
- I915_WRITE(FW_BLC_SELF, I915_READ(FW_BLC_SELF)
- & ~FW_BLC_SELF_EN);
+ if (display_wm > display->max_wm) {
+ DRM_DEBUG_KMS("display watermark is too large(%d), disabling\n",
+ display_wm, display->max_wm);
+ return false;
}
- DRM_DEBUG("Setting FIFO watermarks - A: %d, B: %d, SR %d\n",
- planea_wm, planeb_wm, sr_entries);
+ if (cursor_wm > cursor->max_wm) {
+ DRM_DEBUG_KMS("cursor watermark is too large(%d), disabling\n",
+ cursor_wm, cursor->max_wm);
+ return false;
+ }
- planea_wm &= 0x3f;
- planeb_wm &= 0x3f;
+ if (!(display_wm || cursor_wm)) {
+ DRM_DEBUG_KMS("SR latency is 0, disabling\n");
+ return false;
+ }
- I915_WRITE(DSPFW1, (sr_entries << DSPFW_SR_SHIFT) |
+ return true;
+}
+
+static bool g4x_compute_srwm(struct drm_device *dev,
+ int hdisplay, int htotal,
+ int pixel_size, int clock, int latency_ns,
+ const struct intel_watermark_params *display,
+ const struct intel_watermark_params *cursor,
+ int *display_wm, int *cursor_wm)
+{
+ unsigned long line_time_us;
+ int line_count, line_size;
+ int small, large;
+ int entries;
+
+ if (!latency_ns) {
+ *display_wm = *cursor_wm = 0;
+ return false;
+ }
+
+ line_time_us = (htotal * 1000) / clock;
+ line_count = (latency_ns / line_time_us + 1000) / 1000;
+ line_size = hdisplay * pixel_size;
+
+ /* Use the minimum of the small and large buffer method for primary */
+ small = ((clock * pixel_size / 1000) * latency_ns) / 1000;
+ large = line_count * line_size;
+
+ entries = DIV_ROUND_UP(min(small, large), display->cacheline_size);
+ *display_wm = entries + display->guard_size;
+
+ /* calculate the self-refresh watermark for display cursor */
+ entries = line_count * pixel_size * 64;
+ entries = DIV_ROUND_UP(entries, cursor->cacheline_size);
+ *cursor_wm = entries + cursor->guard_size;
+
+ return g4x_check_srwm(dev,
+ *display_wm, *cursor_wm,
+ display, cursor);
+}
+
+static void g4x_update_wm(struct drm_device *dev,
+ int planea_clock, int planeb_clock,
+ int hdisplay, int htotal, int pixel_size)
+{
+ static const int sr_latency_ns = 12000;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ int planea_wm, planeb_wm, cursora_wm, cursorb_wm;
+ int enabled = 0, plane_sr, cursor_sr, clock;
+
+ if (g4x_compute_wm0(dev, 0,
+ &g4x_wm_info, latency_ns,
+ &g4x_cursor_wm_info, latency_ns,
+ &planea_wm, &cursora_wm))
+ enabled++;
+
+ if (g4x_compute_wm0(dev, 1,
+ &g4x_wm_info, latency_ns,
+ &g4x_cursor_wm_info, latency_ns,
+ &planeb_wm, &cursorb_wm))
+ enabled++;
+
+ plane_sr = cursor_sr = 0;
+ clock = planea_clock ? planea_clock : planeb_clock;
+ if (enabled == 1 &&
+ g4x_compute_srwm(dev, hdisplay, htotal, pixel_size,
+ clock, sr_latency_ns,
+ &g4x_wm_info,
+ &g4x_cursor_wm_info,
+ &plane_sr, &cursor_sr))
+ I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN);
+ else
+ I915_WRITE(FW_BLC_SELF,
+ I915_READ(FW_BLC_SELF) & ~FW_BLC_SELF_EN);
+
+ DRM_DEBUG("Setting FIFO watermarks - A: plane=%d, cursor=%d, B: plane=%d, cursor=%d, SR: plane=%d, cursor=%d\n",
+ planea_wm, cursora_wm,
+ planeb_wm, cursorb_wm,
+ plane_sr, cursor_sr);
+
+ I915_WRITE(DSPFW1,
+ (plane_sr << DSPFW_SR_SHIFT) |
(cursorb_wm << DSPFW_CURSORB_SHIFT) |
- (planeb_wm << DSPFW_PLANEB_SHIFT) | planea_wm);
- I915_WRITE(DSPFW2, (I915_READ(DSPFW2) & DSPFW_CURSORA_MASK) |
+ (planeb_wm << DSPFW_PLANEB_SHIFT) |
+ planea_wm);
+ I915_WRITE(DSPFW2,
+ (I915_READ(DSPFW2) & DSPFW_CURSORA_MASK) |
(cursora_wm << DSPFW_CURSORA_SHIFT));
/* HPLL off in SR has some issues on G4x... disable it */
- I915_WRITE(DSPFW3, (I915_READ(DSPFW3) & ~DSPFW_HPLL_SR_EN) |
+ I915_WRITE(DSPFW3,
+ (I915_READ(DSPFW3) & ~DSPFW_HPLL_SR_EN) |
(cursor_sr << DSPFW_CURSOR_SR_SHIFT));
}
@@ -3743,8 +3831,8 @@
srwm);
/* 965 has limitations... */
- I915_WRITE(DSPFW1, (srwm << DSPFW_SR_SHIFT) | (8 << 16) | (8 << 8) |
- (8 << 0));
+ I915_WRITE(DSPFW1, (srwm << DSPFW_SR_SHIFT) |
+ (8 << 16) | (8 << 8) | (8 << 0));
I915_WRITE(DSPFW2, (8 << 8) | (8 << 0));
/* update cursor SR watermark */
I915_WRITE(DSPFW3, (cursor_sr << DSPFW_CURSOR_SR_SHIFT));
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 74db255..5ce4a5f 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -217,6 +217,13 @@
return dev_priv->pipe_to_crtc_mapping[pipe];
}
+static inline struct drm_crtc *
+intel_get_crtc_for_plane(struct drm_device *dev, int plane)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ return dev_priv->plane_to_crtc_mapping[plane];
+}
+
struct intel_unpin_work {
struct work_struct work;
struct drm_device *dev;