[PATCH 6/7] ath10k: enable alt data of TX path for sdio

[Wen Gong <wgong@codeaurora.org>]

The default credit size is 1792 bytes, but the IP mtu is 1500 bytes,
then it has about 290 bytes's waste for each data packet on sdio
transfer path for TX bundle, it will reduce the transmission utilization
ratio for data packet.

This patch enable the small credit size in firmware, firmware will use
the new credit size 1556 bytes, it will increase the transmission
utilization ratio for data packet on TX patch. It results in significant
performance improvement on TX path.

This patch only effect sdio chip, it will not effect PCI, SNOC etc.

Tested with QCA6174 SDIO with firmware
WLAN.RMH.4.4.1-00017-QCARMSWP-1.

Signed-off-by: Wen Gong <wgong@codeaurora.org>
---
 drivers/net/wireless/ath/ath10k/core.c | 16 ++++++++++++++++
 drivers/net/wireless/ath/ath10k/htc.c  | 11 +++++++++--
 drivers/net/wireless/ath/ath10k/htc.h  | 11 +++++++++--
 3 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
index 351f4ed..7593d19 100644
--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -31,6 +31,7 @@
 static unsigned int ath10k_cryptmode_param;
 static bool uart_print;
 static bool disable_tx_comp = true;
+static bool alt_data = true;
 static bool skip_otp;
 static bool rawmode;
 static bool fw_diag_log;
@@ -45,6 +46,15 @@
 
 /* If upper layer need the TX complete status, it can enable tx complete */
 module_param(disable_tx_comp, bool, 0644);
+
+/* alt_data is only used for sdio chip, for previous version of firmware, its
+ * alt data size is 1544 which is not enough for native wifi, so it need to
+ * alt_data for the firmware.
+ * If the firmware has changed alt data size to 1556, then it can enable
+ * alt_data for the firmware.
+ * alt_data will not effect PCI, SNOC etc.
+ */
+module_param(alt_data, bool, 0644);
 module_param(skip_otp, bool, 0644);
 module_param(rawmode, bool, 0644);
 module_param(fw_diag_log, bool, 0644);
@@ -701,6 +711,12 @@ static void ath10k_init_sdio(struct ath10k *ar, enum ath10k_firmware_mode mode)
 	 */
 	param &= ~HI_ACS_FLAGS_ALT_DATA_CREDIT_SIZE;
 
+	/* If alternate credit size of 1556 as used by SDIO firmware is
+	 * big enough for mac80211 / native wifi frames. enable it
+	 */
+	if (alt_data && mode == ATH10K_FIRMWARE_MODE_NORMAL)
+		param |= HI_ACS_FLAGS_ALT_DATA_CREDIT_SIZE;
+
 	if (mode == ATH10K_FIRMWARE_MODE_UTF)
 		param &= ~HI_ACS_FLAGS_SDIO_SWAP_MAILBOX_SET;
 	else
diff --git a/drivers/net/wireless/ath/ath10k/htc.c b/drivers/net/wireless/ath/ath10k/htc.c
index 96b620f..2db7f1a 100644
--- a/drivers/net/wireless/ath/ath10k/htc.c
+++ b/drivers/net/wireless/ath/ath10k/htc.c
@@ -938,12 +938,15 @@ int ath10k_htc_wait_target(struct ath10k_htc *htc)
 	 */
 	if (htc->control_resp_len >=
 	    sizeof(msg->hdr) + sizeof(msg->ready_ext)) {
+		htc->alt_data_credit_size =
+			__le16_to_cpu(msg->ready_ext.reserved) & 0x0fff;
 		htc->max_msgs_per_htc_bundle =
 			min_t(u8, msg->ready_ext.max_msgs_per_htc_bundle,
 			      HTC_HOST_MAX_MSG_PER_RX_BUNDLE);
 		ath10k_dbg(ar, ATH10K_DBG_HTC,
-			   "Extended ready message. RX bundle size: %d\n",
-			   htc->max_msgs_per_htc_bundle);
+			   "Extended ready message. RX bundle size: %d, alt size:%d\n",
+			   htc->max_msgs_per_htc_bundle,
+			   htc->alt_data_credit_size);
 	}
 
 	INIT_WORK(&ar->bundle_tx_work, ath10k_htc_bundle_tx_work);
@@ -1096,6 +1099,10 @@ int ath10k_htc_connect_service(struct ath10k_htc *htc,
 	ep->tx_credits = tx_alloc;
 	ep->tx_credit_size = htc->target_credit_size;
 
+	if (conn_req->service_id == ATH10K_HTC_SVC_ID_HTT_DATA_MSG &&
+	    htc->alt_data_credit_size != 0)
+		ep->tx_credit_size = htc->alt_data_credit_size;
+
 	/* copy all the callbacks */
 	ep->ep_ops = conn_req->ep_ops;
 
diff --git a/drivers/net/wireless/ath/ath10k/htc.h b/drivers/net/wireless/ath/ath10k/htc.h
index 621ac89..f965b5b 100644
--- a/drivers/net/wireless/ath/ath10k/htc.h
+++ b/drivers/net/wireless/ath/ath10k/htc.h
@@ -135,8 +135,14 @@ struct ath10k_htc_ready_extended {
 	struct ath10k_htc_ready base;
 	u8 htc_version; /* @enum ath10k_htc_version */
 	u8 max_msgs_per_htc_bundle;
-	u8 pad0;
-	u8 pad1;
+	union {
+		__le16 reserved;
+		struct {
+			u8 pad0;
+			u8 pad1;
+		} __packed;
+	} __packed;
+
 } __packed;
 
 struct ath10k_htc_conn_svc {
@@ -373,6 +379,7 @@ struct ath10k_htc {
 	int total_transmit_credits;
 	int target_credit_size;
 	u8 max_msgs_per_htc_bundle;
+	int alt_data_credit_size;
 };
 
 int ath10k_htc_init(struct ath10k *ar);
-- 
1.9.1