[Intel-gfx] [PATCH 1/2] drm/i915/display: Do both crawl and squash when changing cdclk
Anusha Srivatsa
anusha.srivatsa at intel.com
Mon Oct 31 22:56:47 UTC 2022
From: Ville Syrjälä <ville.syrjala at linux.intel.com>
For MTL, changing cdclk from between certain frequencies has
both squash and crawl. Use the current cdclk config and
the new(desired) cdclk config to construtc a mid cdclk config.
Set the cdclk twice:
- Current cdclk -> mid cdclk
- mid cdclk -> desired cdclk
v2: Add check in intel_modeset_calc_cdclk() to avoid cdclk
change via modeset for platforms that support squash_crawl sequences(Ville)
v3: Add checks for:
- scenario where only slow clock is used and
cdclk is actually 0 (bringing up display).
- PLLs are on before looking up the waveform.
- Squash and crawl capability checks.(Ville)
v4: Rebase
- Move checks to be more consistent (Ville)
- Add comments (Bala)
v5:
- Further small changes. Move checks around.
- Make if-else better looking (Ville)
Cc: Balasubramani Vivekanandan <balasubramani.vivekanandan at intel.com>
Signed-off-by: Anusha Srivatsa <anusha.srivatsa at intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
drivers/gpu/drm/i915/display/intel_cdclk.c | 156 +++++++++++++++++----
1 file changed, 128 insertions(+), 28 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
index eada931cb1c8..d79cf282faa8 100644
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -1716,37 +1716,74 @@ static void dg2_cdclk_squash_program(struct drm_i915_private *i915,
intel_de_write(i915, CDCLK_SQUASH_CTL, squash_ctl);
}
-static void bxt_set_cdclk(struct drm_i915_private *dev_priv,
- const struct intel_cdclk_config *cdclk_config,
- enum pipe pipe)
+static int cdclk_squash_divider(u16 waveform)
+{
+ return hweight16(waveform ?: 0xffff);
+}
+
+static bool cdclk_crawl_and_squash(struct drm_i915_private *i915,
+ const struct intel_cdclk_config *old_cdclk_config,
+ const struct intel_cdclk_config *new_cdclk_config,
+ struct intel_cdclk_config *mid_cdclk_config)
+{
+ u16 old_waveform, new_waveform, mid_waveform;
+ int size = 16;
+ int div = 2;
+
+ /* Return if both Squash and Crawl are not present */
+ if (!HAS_CDCLK_CRAWL(i915) || !HAS_CDCLK_SQUASH(i915))
+ return false;
+
+ old_waveform = cdclk_squash_waveform(i915, old_cdclk_config->cdclk);
+ new_waveform = cdclk_squash_waveform(i915, new_cdclk_config->cdclk);
+
+ /* Return if Squash only or Crawl only is the desired action */
+ if (old_cdclk_config->vco <= 0 || new_cdclk_config->vco <= 0 ||
+ old_cdclk_config->vco == new_cdclk_config->vco ||
+ old_waveform == new_waveform)
+ return false;
+
+ *mid_cdclk_config = *new_cdclk_config;
+
+ /* Populate the mid_cdclk_config accordingly.
+ * - If moving to a higher cdclk, the desired action is squashing.
+ * The mid cdclk config should have the new (squash) waveform.
+ * - If moving to a lower cdclk, the desired action is crawling.
+ * The mid cdclk config should have the new vco.
+ */
+
+ if (cdclk_squash_divider(new_waveform) > cdclk_squash_divider(old_waveform)) {
+ mid_cdclk_config->vco = old_cdclk_config->vco;
+ mid_waveform = new_waveform;
+ } else {
+ mid_cdclk_config->vco = new_cdclk_config->vco;
+ mid_waveform = old_waveform;
+ }
+
+ mid_cdclk_config->cdclk = DIV_ROUND_CLOSEST(cdclk_squash_divider(mid_waveform) *
+ mid_cdclk_config->vco, size * div);
+
+ /* make sure the mid clock came out sane */
+
+ drm_WARN_ON(&i915->drm, mid_cdclk_config->cdclk <
+ min(old_cdclk_config->cdclk, new_cdclk_config->cdclk));
+ drm_WARN_ON(&i915->drm, mid_cdclk_config->cdclk >
+ i915->display.cdclk.max_cdclk_freq);
+ drm_WARN_ON(&i915->drm, cdclk_squash_waveform(i915, mid_cdclk_config->cdclk) !=
+ mid_waveform);
+
+ return true;
+}
+
+static void _bxt_set_cdclk(struct drm_i915_private *dev_priv,
+ const struct intel_cdclk_config *cdclk_config,
+ enum pipe pipe)
{
int cdclk = cdclk_config->cdclk;
int vco = cdclk_config->vco;
u32 val;
u16 waveform;
int clock;
- int ret;
-
- /* Inform power controller of upcoming frequency change. */
- if (DISPLAY_VER(dev_priv) >= 11)
- ret = skl_pcode_request(&dev_priv->uncore, SKL_PCODE_CDCLK_CONTROL,
- SKL_CDCLK_PREPARE_FOR_CHANGE,
- SKL_CDCLK_READY_FOR_CHANGE,
- SKL_CDCLK_READY_FOR_CHANGE, 3);
- else
- /*
- * BSpec requires us to wait up to 150usec, but that leads to
- * timeouts; the 2ms used here is based on experiment.
- */
- ret = snb_pcode_write_timeout(&dev_priv->uncore,
- HSW_PCODE_DE_WRITE_FREQ_REQ,
- 0x80000000, 150, 2);
- if (ret) {
- drm_err(&dev_priv->drm,
- "Failed to inform PCU about cdclk change (err %d, freq %d)\n",
- ret, cdclk);
- return;
- }
if (HAS_CDCLK_CRAWL(dev_priv) && dev_priv->display.cdclk.hw.vco > 0 && vco > 0) {
if (dev_priv->display.cdclk.hw.vco != vco)
@@ -1781,6 +1818,44 @@ static void bxt_set_cdclk(struct drm_i915_private *dev_priv,
if (pipe != INVALID_PIPE)
intel_crtc_wait_for_next_vblank(intel_crtc_for_pipe(dev_priv, pipe));
+}
+
+static void bxt_set_cdclk(struct drm_i915_private *dev_priv,
+ const struct intel_cdclk_config *cdclk_config,
+ enum pipe pipe)
+{
+ struct intel_cdclk_config mid_cdclk_config;
+ int cdclk = cdclk_config->cdclk;
+ int ret;
+
+ /* Inform power controller of upcoming frequency change. */
+ if (DISPLAY_VER(dev_priv) >= 11)
+ ret = skl_pcode_request(&dev_priv->uncore, SKL_PCODE_CDCLK_CONTROL,
+ SKL_CDCLK_PREPARE_FOR_CHANGE,
+ SKL_CDCLK_READY_FOR_CHANGE,
+ SKL_CDCLK_READY_FOR_CHANGE, 3);
+ else
+ /*
+ * BSpec requires us to wait up to 150usec, but that leads to
+ * timeouts; the 2ms used here is based on experiment.
+ */
+ ret = snb_pcode_write_timeout(&dev_priv->uncore,
+ HSW_PCODE_DE_WRITE_FREQ_REQ,
+ 0x80000000, 150, 2);
+ if (ret) {
+ drm_err(&dev_priv->drm,
+ "Failed to inform PCU about cdclk change (err %d, freq %d)\n",
+ ret, cdclk);
+ return;
+ }
+
+ if (cdclk_crawl_and_squash(dev_priv, &dev_priv->display.cdclk.hw,
+ cdclk_config, &mid_cdclk_config)) {
+ _bxt_set_cdclk(dev_priv, &mid_cdclk_config, pipe);
+ _bxt_set_cdclk(dev_priv, cdclk_config, pipe);
+ } else {
+ _bxt_set_cdclk(dev_priv, cdclk_config, pipe);
+ }
if (DISPLAY_VER(dev_priv) >= 11) {
ret = snb_pcode_write(&dev_priv->uncore, SKL_PCODE_CDCLK_CONTROL,
@@ -1953,6 +2028,26 @@ void intel_cdclk_uninit_hw(struct drm_i915_private *i915)
skl_cdclk_uninit_hw(i915);
}
+static bool intel_cdclk_can_crawl_and_squash(struct drm_i915_private *i915,
+ const struct intel_cdclk_config *a,
+ const struct intel_cdclk_config *b)
+{
+ u16 old_waveform;
+ u16 new_waveform;
+
+ if (a->vco == 0 || b->vco == 0)
+ return false;
+
+ if (!HAS_CDCLK_CRAWL(i915) && !HAS_CDCLK_SQUASH(i915))
+ return false;
+
+ old_waveform = cdclk_squash_waveform(i915, a->cdclk);
+ new_waveform = cdclk_squash_waveform(i915, b->cdclk);
+
+ return a->vco != b->vco &&
+ old_waveform != new_waveform;
+}
+
static bool intel_cdclk_can_crawl(struct drm_i915_private *dev_priv,
const struct intel_cdclk_config *a,
const struct intel_cdclk_config *b)
@@ -2759,9 +2854,14 @@ int intel_modeset_calc_cdclk(struct intel_atomic_state *state)
pipe = INVALID_PIPE;
}
- if (intel_cdclk_can_squash(dev_priv,
- &old_cdclk_state->actual,
- &new_cdclk_state->actual)) {
+ if (intel_cdclk_can_crawl_and_squash(dev_priv,
+ &old_cdclk_state->actual,
+ &new_cdclk_state->actual)) {
+ drm_dbg_kms(&dev_priv->drm,
+ "Can change cdclk via crawling and squashing\n");
+ } else if (intel_cdclk_can_squash(dev_priv,
+ &old_cdclk_state->actual,
+ &new_cdclk_state->actual)) {
drm_dbg_kms(&dev_priv->drm,
"Can change cdclk via squashing\n");
} else if (intel_cdclk_can_crawl(dev_priv,
--
2.25.1
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