ath11k: Disabling credit flow for WMI path

Firmware credit flow control is enabled for WMI control services,
which expects available tokens should be acquired before sending a
command to the target. Also the token gets released when firmware
receives the command.

This credit-based flow limits driver to send WMI command only
when the token available which is causing WMI commands to timeout and
return -EAGAIN, whereas firmware has enough capability to process the
WMI command. To fix this Tx starvation issue, introduce the ability to
disable the credit flow for the WMI path.

The driver sends WMI configuration for disabling credit flow to firmware
by two ways.
	1. By using a global flag
		(HTC_MSG_SETUP_COMPLETE_EX_ID msg type flags)
	2. By using a local flag
		(ATH11K_HTC_CONN_FLAGS_DISABLE_CREDIT_FLOW_CTRL = 1 << 3)

Ath11k uses both these configurations to disable credit flow for the
WMI path completely.

Also added a hw_param member for credit flow control by which we can
enable or disable it based on per-target basis. Currently we are disabling
credit flow for IPQ8074, IPQ6018, and QCN9074 as recommended by firmware.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.4.0.1-01492-QCAHKSWPL_SILICONZ-1
Tested-on: IPQ6018 hw1.0 AHB WLAN.HK.2.4.0.1-00330-QCAHKSWPL_SILICONZ-1

Co-developed-by: Pravas Kumar Panda <kumarpan@codeaurora.org>
Signed-off-by: Pravas Kumar Panda <kumarpan@codeaurora.org>
Signed-off-by: P Praneesh <quic_ppranees@quicinc.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1635156494-20059-1-git-send-email-quic_ppranees@quicinc.com

1 files changed, 48 insertions, 6 deletions

diff --git a/drivers/net/wireless/ath/ath11k/wmi.c b/drivers/net/wireless/ath/ath11k/wmi.c
index 6248e174bd8f..6bd355ce88d3 100644
--- a/drivers/net/wireless/ath/ath11k/wmi.c
+++ b/drivers/net/wireless/ath/ath11k/wmi.c
@@ -267,21 +267,39 @@ int ath11k_wmi_cmd_send(struct ath11k_pdev_wmi *wmi, struct sk_buff *skb,
 {
 	struct ath11k_wmi_base *wmi_sc = wmi->wmi_ab;
 	int ret = -EOPNOTSUPP;
+	struct ath11k_base *ab = wmi_sc->ab;
 
 	might_sleep();
 
-	wait_event_timeout(wmi_sc->tx_credits_wq, ({
-		ret = ath11k_wmi_cmd_send_nowait(wmi, skb, cmd_id);
+	if (ab->hw_params.credit_flow) {
+		wait_event_timeout(wmi_sc->tx_credits_wq, ({
+			ret = ath11k_wmi_cmd_send_nowait(wmi, skb, cmd_id);
+
+			if (ret && test_bit(ATH11K_FLAG_CRASH_FLUSH,
+					    &wmi_sc->ab->dev_flags))
+				ret = -ESHUTDOWN;
 
-		if (ret && test_bit(ATH11K_FLAG_CRASH_FLUSH, &wmi_sc->ab->dev_flags))
-			ret = -ESHUTDOWN;
+			(ret != -EAGAIN);
+			}), WMI_SEND_TIMEOUT_HZ);
+	} else {
+		wait_event_timeout(wmi->tx_ce_desc_wq, ({
+			ret = ath11k_wmi_cmd_send_nowait(wmi, skb, cmd_id);
 
-		(ret != -EAGAIN);
-	}), WMI_SEND_TIMEOUT_HZ);
+			if (ret && test_bit(ATH11K_FLAG_CRASH_FLUSH,
+					    &wmi_sc->ab->dev_flags))
+				ret = -ESHUTDOWN;
+
+			(ret != -ENOBUFS);
+			}), WMI_SEND_TIMEOUT_HZ);
+	}
 
 	if (ret == -EAGAIN)
 		ath11k_warn(wmi_sc->ab, "wmi command %d timeout\n", cmd_id);
 
+	if (ret == -ENOBUFS)
+		ath11k_warn(wmi_sc->ab, "ce desc not available for wmi command %d\n",
+			    cmd_id);
+
 	return ret;
 }
 
@@ -5816,7 +5834,30 @@ static void ath11k_wmi_op_ep_tx_credits(struct ath11k_base *ab)
 static void ath11k_wmi_htc_tx_complete(struct ath11k_base *ab,
 				       struct sk_buff *skb)
 {
+	struct ath11k_pdev_wmi *wmi = NULL;
+	u32 i;
+	u8 wmi_ep_count;
+	u8 eid;
+
+	eid = ATH11K_SKB_CB(skb)->eid;
 	dev_kfree_skb(skb);
+
+	if (eid >= ATH11K_HTC_EP_COUNT)
+		return;
+
+	wmi_ep_count = ab->htc.wmi_ep_count;
+	if (wmi_ep_count > ab->hw_params.max_radios)
+		return;
+
+	for (i = 0; i < ab->htc.wmi_ep_count; i++) {
+		if (ab->wmi_ab.wmi[i].eid == eid) {
+			wmi = &ab->wmi_ab.wmi[i];
+			break;
+		}
+	}
+
+	if (wmi)
+		wake_up(&wmi->tx_ce_desc_wq);
 }
 
 static bool ath11k_reg_is_world_alpha(char *alpha)
@@ -7207,6 +7248,7 @@ static int ath11k_connect_pdev_htc_service(struct ath11k_base *ab,
 	ab->wmi_ab.wmi_endpoint_id[pdev_idx] = conn_resp.eid;
 	ab->wmi_ab.wmi[pdev_idx].eid = conn_resp.eid;
 	ab->wmi_ab.max_msg_len[pdev_idx] = conn_resp.max_msg_len;
+	init_waitqueue_head(&ab->wmi_ab.wmi[pdev_idx].tx_ce_desc_wq);
 
 	return 0;
 }