qcacmn: Check tx completions pending before disabling pipes

wlan Tx completions doorbell is rung after IPA pipes are disabled
To fix this, Check if tx completions are pending before disable IPA
pipes.

Change-Id: I1903e593cd6a546a277979073f0a9ba62b681644
CRs-Fixed: 2796989

dp/wifi3.0/dp_ipa.c

@@ -1778,11 +1778,40 @@ QDF_STATUS dp_ipa_enable_pipes(struct cdp_soc_t *soc_hdl, uint8_t pdev_id)
 	return QDF_STATUS_SUCCESS;
 }
 
+/*
+ * dp_ipa_get_tx_comp_pending_check() - Check if tx completions are pending.
+ * @soc: DP pdev Context
+ *
+ * Ring full condition is checked to find if buffers are left for
+ * processing as host only allocates buffers in this ring and IPA HW processes
+ * the buffer.
+ *
+ * Return: True if tx completions are pending
+ */
+static bool dp_ipa_get_tx_comp_pending_check(struct dp_soc *soc)
+{
+	struct dp_srng *tx_comp_ring =
+				&soc->tx_comp_ring[IPA_TX_COMP_RING_IDX];
+	uint32_t hp, tp, entry_size, buf_cnt;
+
+	hal_get_hw_hptp(soc->hal_soc, tx_comp_ring->hal_srng, &hp, &tp,
+			WBM2SW_RELEASE);
+	entry_size = hal_srng_get_entrysize(soc->hal_soc, WBM2SW_RELEASE) >> 2;
+
+	if (hp > tp)
+		buf_cnt = (hp - tp) / entry_size;
+	else
+		buf_cnt = (tx_comp_ring->num_entries - tp + hp) / entry_size;
+
+	return (soc->ipa_uc_tx_rsc.alloc_tx_buf_cnt != buf_cnt);
+}
+
 QDF_STATUS dp_ipa_disable_pipes(struct cdp_soc_t *soc_hdl, uint8_t pdev_id)
 {
 	struct dp_soc *soc = cdp_soc_t_to_dp_soc(soc_hdl);
 	struct dp_pdev *pdev =
 		dp_get_pdev_from_soc_pdev_id_wifi3(soc, pdev_id);
+	int timeout = TX_COMP_DRAIN_WAIT_TIMEOUT_MS;
 	QDF_STATUS result;
 
 	if (!pdev) {
@@ -1790,6 +1819,15 @@ QDF_STATUS dp_ipa_disable_pipes(struct cdp_soc_t *soc_hdl, uint8_t pdev_id)
 		return QDF_STATUS_E_FAILURE;
 	}
 
+	while (dp_ipa_get_tx_comp_pending_check(soc)) {
+		qdf_sleep(TX_COMP_DRAIN_WAIT_MS);
+		timeout -= TX_COMP_DRAIN_WAIT_MS;
+		if (timeout <= 0) {
+			dp_err("Tx completions pending. Force Disabling pipes");
+			break;
+		}
+	}
+
 	result = qdf_ipa_wdi_disable_pipes();
 	if (result) {
 		QDF_TRACE(QDF_MODULE_ID_TXRX, QDF_TRACE_LEVEL_ERROR,

dp/wifi3.0/dp_ipa.h

@@ -24,6 +24,10 @@
 #define IPA_REO_DEST_RING_IDX	3
 #define IPA_RX_REFILL_BUF_RING_IDX	2
 
+/* Adding delay before disabling ipa pipes if any Tx Completions are pending */
+#define TX_COMP_DRAIN_WAIT_MS	50
+#define TX_COMP_DRAIN_WAIT_TIMEOUT_MS	200
+
 /**
  * struct dp_ipa_uc_tx_hdr - full tx header registered to IPA hardware
  * @eth:     ether II header