dev_priv->cdclk_pll.vco = 0;
}
-static bool skl_cdclk_pcu_ready(struct drm_i915_private *dev_priv)
-{
- int ret;
- u32 val;
-
- /* inform PCU we want to change CDCLK */
- val = SKL_CDCLK_PREPARE_FOR_CHANGE;
- mutex_lock(&dev_priv->rps.hw_lock);
- ret = sandybridge_pcode_read(dev_priv, SKL_PCODE_CDCLK_CONTROL, &val);
- mutex_unlock(&dev_priv->rps.hw_lock);
-
- return ret == 0 && (val & SKL_CDCLK_READY_FOR_CHANGE);
-}
-
-static bool skl_cdclk_wait_for_pcu_ready(struct drm_i915_private *dev_priv)
-{
- return _wait_for(skl_cdclk_pcu_ready(dev_priv), 3000, 10) == 0;
-}
-
static void skl_set_cdclk(struct drm_i915_private *dev_priv, int cdclk, int vco)
{
u32 freq_select, pcu_ack;
+ int ret;
WARN_ON((cdclk == 24000) != (vco == 0));
DRM_DEBUG_DRIVER("Changing CDCLK to %d kHz (VCO %d kHz)\n", cdclk, vco);
- if (!skl_cdclk_wait_for_pcu_ready(dev_priv)) {
- DRM_ERROR("failed to inform PCU about cdclk change\n");
+ mutex_lock(&dev_priv->rps.hw_lock);
+ ret = skl_pcode_request(dev_priv, SKL_PCODE_CDCLK_CONTROL,
+ SKL_CDCLK_PREPARE_FOR_CHANGE,
+ SKL_CDCLK_READY_FOR_CHANGE,
+ SKL_CDCLK_READY_FOR_CHANGE, 3);
+ mutex_unlock(&dev_priv->rps.hw_lock);
+ if (ret) {
+ DRM_ERROR("Failed to inform PCU about cdclk change (%d)\n",
+ ret);
return;
}
return 0;
}
+static bool skl_pcode_try_request(struct drm_i915_private *dev_priv, u32 mbox,
+ u32 request, u32 reply_mask, u32 reply,
+ u32 *status)
+{
+ u32 val = request;
+
+ *status = sandybridge_pcode_read(dev_priv, mbox, &val);
+
+ return *status || ((val & reply_mask) == reply);
+}
+
+/**
+ * skl_pcode_request - send PCODE request until acknowledgment
+ * @dev_priv: device private
+ * @mbox: PCODE mailbox ID the request is targeted for
+ * @request: request ID
+ * @reply_mask: mask used to check for request acknowledgment
+ * @reply: value used to check for request acknowledgment
+ * @timeout_base_ms: timeout for polling with preemption enabled
+ *
+ * Keep resending the @request to @mbox until PCODE acknowledges it, PCODE
+ * reports an error or an overall timeout of @timeout_base_ms+10 ms expires.
+ * The request is acknowledged once the PCODE reply dword equals @reply after
+ * applying @reply_mask. Polling is first attempted with preemption enabled
+ * for @timeout_base_ms and if this times out for another 10 ms with
+ * preemption disabled.
+ *
+ * Returns 0 on success, %-ETIMEDOUT in case of a timeout, <0 in case of some
+ * other error as reported by PCODE.
+ */
+int skl_pcode_request(struct drm_i915_private *dev_priv, u32 mbox, u32 request,
+ u32 reply_mask, u32 reply, int timeout_base_ms)
+{
+ u32 status;
+ int ret;
+
+ WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
+
+#define COND skl_pcode_try_request(dev_priv, mbox, request, reply_mask, reply, \
+ &status)
+
+ /*
+ * Prime the PCODE by doing a request first. Normally it guarantees
+ * that a subsequent request, at most @timeout_base_ms later, succeeds.
+ * _wait_for() doesn't guarantee when its passed condition is evaluated
+ * first, so send the first request explicitly.
+ */
+ if (COND) {
+ ret = 0;
+ goto out;
+ }
+ ret = _wait_for(COND, timeout_base_ms * 1000, 10);
+ if (!ret)
+ goto out;
+
+ /*
+ * The above can time out if the number of requests was low (2 in the
+ * worst case) _and_ PCODE was busy for some reason even after a
+ * (queued) request and @timeout_base_ms delay. As a workaround retry
+ * the poll with preemption disabled to maximize the number of
+ * requests. Increase the timeout from @timeout_base_ms to 10ms to
+ * account for interrupts that could reduce the number of these
+ * requests.
+ */
+ DRM_DEBUG_KMS("PCODE timeout, retrying with preemption disabled\n");
+ WARN_ON_ONCE(timeout_base_ms > 3);
+ preempt_disable();
+ ret = wait_for_atomic(COND, 10);
+ preempt_enable();
+
+out:
+ return ret ? ret : status;
+#undef COND
+}
+
static int byt_gpu_freq(struct drm_i915_private *dev_priv, int val)
{
/*
projects / kernel.git / commitdiff