[Intel-gfx] [PATCH v5 7/8] drm/i915: BDW clock change support
Mika Kahola
mika.kahola at intel.com
Tue Jun 2 00:21:05 PDT 2015
From: Ville Syrjälä <ville.syrjala at linux.intel.com>
Add support for changing cdclk frequency during runtime on BDW. The
procedure is quite a bit different on BDW from the one on HSW, so
add a separate function for it.
Also with IPS enabled the actual pixel rate mustn't exceed 95% of cdclk,
so take that into account when computing the max pixel rate.
v2: Grab rps.hw_lock around sandybridge_pcode_write()
v3: Rebase due to power well vs. .global_resources() reordering
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
v4: Rebased to the latest
v5: Rebased to the latest
v6: Patch order shuffle so that Broadwell CD clock change is
applied before the patch for Haswell CD clock change
Signed-off-by: Mika Kahola <mika.kahola at intel.com>
Author: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
drivers/gpu/drm/i915/i915_reg.h | 2 +
drivers/gpu/drm/i915/intel_display.c | 216 +++++++++++++++++++++++++++++++++--
2 files changed, 208 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 7213224..0f72c0e 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6705,6 +6705,7 @@ enum skl_disp_power_wells {
#define GEN6_PCODE_READ_RC6VIDS 0x5
#define GEN6_ENCODE_RC6_VID(mv) (((mv) - 245) / 5)
#define GEN6_DECODE_RC6_VID(vids) (((vids) * 5) + 245)
+#define BDW_PCODE_DISPLAY_FREQ_CHANGE_REQ 0x18
#define GEN9_PCODE_READ_MEM_LATENCY 0x6
#define GEN9_MEM_LATENCY_LEVEL_MASK 0xFF
#define GEN9_MEM_LATENCY_LEVEL_1_5_SHIFT 8
@@ -7170,6 +7171,7 @@ enum skl_disp_power_wells {
#define LCPLL_CLK_FREQ_337_5_BDW (2<<26)
#define LCPLL_CLK_FREQ_675_BDW (3<<26)
#define LCPLL_CD_CLOCK_DISABLE (1<<25)
+#define LCPLL_ROOT_CD_CLOCK_DISABLE (1<<24)
#define LCPLL_CD2X_CLOCK_DISABLE (1<<23)
#define LCPLL_POWER_DOWN_ALLOW (1<<22)
#define LCPLL_CD_SOURCE_FCLK (1<<21)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 961535e..3f50bb1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5751,7 +5751,22 @@ static void intel_update_max_cdclk(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
- if (IS_VALLEYVIEW(dev)) {
+ if (IS_BROADWELL(dev)) {
+ /*
+ * FIXME with extra cooling we can allow
+ * 540 MHz for ULX and 675 Mhz for ULT.
+ * How can we know if extra cooling is
+ * available? PCI ID, VTB, something else?
+ */
+ if (I915_READ(FUSE_STRAP) & HSW_CDCLK_LIMIT)
+ dev_priv->max_cdclk_freq = 450000;
+ else if (IS_BDW_ULX(dev))
+ dev_priv->max_cdclk_freq = 450000;
+ else if (IS_BDW_ULT(dev))
+ dev_priv->max_cdclk_freq = 540000;
+ else
+ dev_priv->max_cdclk_freq = 675000;
+ } else if (IS_VALLEYVIEW(dev)) {
dev_priv->max_cdclk_freq = 400000;
} else {
/* otherwise assume cdclk is fixed */
@@ -6623,13 +6638,11 @@ static bool pipe_config_supports_ips(struct drm_i915_private *dev_priv,
return true;
/*
- * FIXME if we compare against max we should then
- * increase the cdclk frequency when the current
- * value is too low. The other option is to compare
- * against the cdclk frequency we're going have post
- * modeset (ie. one we computed using other constraints).
- * Need to measure whether using a lower cdclk w/o IPS
- * is better or worse than a higher cdclk w/ IPS.
+ * We compare against max which means we must take
+ * the increased cdclk requirement into account when
+ * calculating the new cdclk.
+ *
+ * Should measure whether using a lower cdclk w/o IPS
*/
return ilk_pipe_pixel_rate(pipe_config) <=
dev_priv->max_cdclk_freq * 95 / 100;
@@ -9610,6 +9623,182 @@ static void broxton_modeset_global_resources(struct drm_atomic_state *old_state)
broxton_set_cdclk(dev, req_cdclk);
}
+/* compute the max rate for new configuration */
+static int ilk_max_pixel_rate(struct drm_i915_private *dev_priv)
+{
+ struct drm_device *dev = dev_priv->dev;
+ struct intel_crtc *intel_crtc;
+ struct drm_crtc *crtc;
+ int max_pixel_rate = 0;
+ int pixel_rate;
+
+ for_each_crtc(dev, crtc) {
+ if (!crtc->state->enable)
+ continue;
+
+ intel_crtc = to_intel_crtc(crtc);
+ pixel_rate = ilk_pipe_pixel_rate(intel_crtc->config);
+
+ /* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
+ if (IS_BROADWELL(dev) && intel_crtc->config->ips_enabled)
+ pixel_rate = DIV_ROUND_UP(pixel_rate * 100, 95);
+
+ max_pixel_rate = max(max_pixel_rate, pixel_rate);
+ }
+
+ return max_pixel_rate;
+}
+
+static void broadwell_set_cdclk(struct drm_device *dev, int cdclk)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ uint32_t val, data;
+ int ret;
+
+ if (WARN((I915_READ(LCPLL_CTL) &
+ (LCPLL_PLL_DISABLE | LCPLL_PLL_LOCK |
+ LCPLL_CD_CLOCK_DISABLE | LCPLL_ROOT_CD_CLOCK_DISABLE |
+ LCPLL_CD2X_CLOCK_DISABLE | LCPLL_POWER_DOWN_ALLOW |
+ LCPLL_CD_SOURCE_FCLK)) != LCPLL_PLL_LOCK,
+ "trying to change cdclk frequency with cdclk not enabled\n"))
+ return;
+
+ mutex_lock(&dev_priv->rps.hw_lock);
+ ret = sandybridge_pcode_write(dev_priv,
+ BDW_PCODE_DISPLAY_FREQ_CHANGE_REQ, 0x0);
+ mutex_unlock(&dev_priv->rps.hw_lock);
+ if (ret) {
+ DRM_ERROR("failed to inform pcode about cdclk change\n");
+ return;
+ }
+
+ val = I915_READ(LCPLL_CTL);
+ val |= LCPLL_CD_SOURCE_FCLK;
+ I915_WRITE(LCPLL_CTL, val);
+
+ if (wait_for_atomic_us(I915_READ(LCPLL_CTL) &
+ LCPLL_CD_SOURCE_FCLK_DONE, 1))
+ DRM_ERROR("Switching to FCLK failed\n");
+
+ val = I915_READ(LCPLL_CTL);
+ val &= ~LCPLL_CLK_FREQ_MASK;
+
+ switch (cdclk) {
+ case 450000:
+ val |= LCPLL_CLK_FREQ_450;
+ data = 0;
+ break;
+ case 540000:
+ val |= LCPLL_CLK_FREQ_54O_BDW;
+ data = 1;
+ break;
+ case 337500:
+ val |= LCPLL_CLK_FREQ_337_5_BDW;
+ data = 2;
+ break;
+ case 675000:
+ val |= LCPLL_CLK_FREQ_675_BDW;
+ data = 3;
+ break;
+ default:
+ WARN(1, "invalid cdclk frequency\n");
+ return;
+ }
+
+ I915_WRITE(LCPLL_CTL, val);
+
+ val = I915_READ(LCPLL_CTL);
+ val &= ~LCPLL_CD_SOURCE_FCLK;
+ I915_WRITE(LCPLL_CTL, val);
+
+ if (wait_for_atomic_us((I915_READ(LCPLL_CTL) &
+ LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1))
+ DRM_ERROR("Switching back to LCPLL failed\n");
+
+ mutex_lock(&dev_priv->rps.hw_lock);
+ sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ, data);
+ mutex_unlock(&dev_priv->rps.hw_lock);
+
+ intel_update_cdclk(dev);
+
+ WARN(cdclk != dev_priv->cdclk_freq,
+ "cdclk requested %d kHz but got %d kHz\n",
+ cdclk, dev_priv->cdclk_freq);
+}
+
+static int broadwell_calc_cdclk(struct drm_i915_private *dev_priv,
+ int max_pixel_rate)
+{
+ int cdclk;
+
+ /*
+ * FIXME should also account for plane ratio
+ * once 64bpp pixel formats are supported.
+ */
+ if (max_pixel_rate > 540000)
+ cdclk = 675000;
+ else if (max_pixel_rate > 450000)
+ cdclk = 540000;
+ else if (max_pixel_rate > 337500)
+ cdclk = 450000;
+ else
+ cdclk = 337500;
+
+ /*
+ * FIXME move the cdclk caclulation to
+ * compute_config() so we can fail gracegully.
+ */
+ if (cdclk > dev_priv->max_cdclk_freq) {
+ DRM_ERROR("requested cdclk (%d kHz) exceeds max (%d kHz)\n",
+ cdclk, dev_priv->max_cdclk_freq);
+ cdclk = dev_priv->max_cdclk_freq;
+ }
+
+ return cdclk;
+}
+
+static int broadwell_modeset_global_pipes(struct drm_atomic_state *state)
+{
+ struct drm_i915_private *dev_priv = to_i915(state->dev);
+ struct drm_crtc *crtc;
+ struct drm_crtc_state *crtc_state;
+ int max_pixclk = ilk_max_pixel_rate(dev_priv);
+ int cdclk, i;
+
+ cdclk = broadwell_calc_cdclk(dev_priv, max_pixclk);
+
+ if (cdclk == dev_priv->cdclk_freq)
+ return 0;
+
+ /* add all active pipes to the state */
+ for_each_crtc(state->dev, crtc) {
+ if (!crtc->state->enable)
+ continue;
+
+ crtc_state = drm_atomic_get_crtc_state(state, crtc);
+ if (IS_ERR(crtc_state))
+ return PTR_ERR(crtc_state);
+ }
+
+ /* disable/enable all currently active pipes while we change cdclk */
+ for_each_crtc_in_state(state, crtc, crtc_state, i)
+ if (crtc_state->enable)
+ crtc_state->mode_changed = true;
+
+ return 0;
+}
+
+static void broadwell_modeset_global_resources(struct drm_atomic_state *state)
+{
+ struct drm_device *dev = state->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ int max_pixel_rate = ilk_max_pixel_rate(dev_priv);
+ int req_cdclk = broadwell_calc_cdclk(dev_priv, max_pixel_rate);
+
+ if (req_cdclk != dev_priv->cdclk_freq)
+ broadwell_set_cdclk(dev, req_cdclk);
+}
+
static int haswell_crtc_compute_clock(struct intel_crtc *crtc,
struct intel_crtc_state *crtc_state)
{
@@ -12790,8 +12979,12 @@ static int __intel_set_mode_checks(struct drm_atomic_state *state)
* mode set on this crtc. For other crtcs we need to use the
* adjusted_mode bits in the crtc directly.
*/
- if (IS_VALLEYVIEW(dev) || IS_BROXTON(dev)) {
- ret = valleyview_modeset_global_pipes(state);
+ if (IS_VALLEYVIEW(dev) || IS_BROXTON(dev) || IS_BROADWELL(dev)) {
+ if (IS_VALLEYVIEW(dev) || IS_BROXTON(dev))
+ ret = valleyview_modeset_global_pipes(state);
+ else
+ ret = broadwell_modeset_global_pipes(state);
+
if (ret)
return ret;
}
@@ -14679,6 +14872,9 @@ static void intel_init_display(struct drm_device *dev)
dev_priv->display.fdi_link_train = ivb_manual_fdi_link_train;
} else if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
dev_priv->display.fdi_link_train = hsw_fdi_link_train;
+ if (IS_BROADWELL(dev))
+ dev_priv->display.modeset_global_resources =
+ broadwell_modeset_global_resources;
} else if (IS_VALLEYVIEW(dev)) {
dev_priv->display.modeset_global_resources =
valleyview_modeset_global_resources;
--
1.9.1
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