[PATCH 03/11] wil6210: support 8KB RX buffers

[Maya Erez <qca_merez@qca.qualcomm.com>]

From: Lior David <qca_liord@qca.qualcomm.com>

The 11ad spec requires 11ad devices to be able to receive 8KB
packets over the air. Currently this is only possible by
loading the driver with mtu_max=7912 but this also forces
a smaller block ACK window size which reduces performance
for stations which transmit normal sized packets (<2KB).
Fix this problem as follows:
1. Add a module parameter rx_large_buf that when set,
will allocate 8KB RX buffers regardless of mtu_max
setting.
2. When receiving block ACK request agree to any window
size not above our maximum, regardless of the mtu_max setting.
This means if the other side transmits small packets (2KB)
it can still set up block ACK with a large window size,
and get better performance.

Signed-off-by: Lior David <qca_liord@qca.qualcomm.com>
Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
---
 drivers/net/wireless/ath/wil6210/rx_reorder.c | 12 ++++++++++--
 drivers/net/wireless/ath/wil6210/txrx.c       | 24 ++++++++++++++++++++++--
 drivers/net/wireless/ath/wil6210/wil6210.h    |  2 ++
 drivers/net/wireless/ath/wil6210/wmi.c        |  3 ++-
 4 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/ath/wil6210/rx_reorder.c b/drivers/net/wireless/ath/wil6210/rx_reorder.c
index 7404b6f..a43cffc 100644
--- a/drivers/net/wireless/ath/wil6210/rx_reorder.c
+++ b/drivers/net/wireless/ath/wil6210/rx_reorder.c
@@ -343,8 +343,16 @@ int wil_addba_rx_request(struct wil6210_priv *wil, u8 cidxtid,
 		wil_err(wil, "BACK requested unsupported ba_policy == 1\n");
 		status = WLAN_STATUS_INVALID_QOS_PARAM;
 	}
-	if (status == WLAN_STATUS_SUCCESS)
-		agg_wsize = wil_agg_size(wil, req_agg_wsize);
+	if (status == WLAN_STATUS_SUCCESS) {
+		if (req_agg_wsize == 0) {
+			wil_dbg_misc(wil, "Suggest BACK wsize %d\n",
+				     WIL_MAX_AGG_WSIZE);
+			agg_wsize = WIL_MAX_AGG_WSIZE;
+		} else {
+			agg_wsize = min_t(u16,
+					  WIL_MAX_AGG_WSIZE, req_agg_wsize);
+		}
+	}
 
 	rc = wmi_addba_rx_resp(wil, cid, tid, dialog_token, status,
 			       agg_amsdu, agg_wsize, agg_timeout);
diff --git a/drivers/net/wireless/ath/wil6210/txrx.c b/drivers/net/wireless/ath/wil6210/txrx.c
index 67f50ae..edab4c0 100644
--- a/drivers/net/wireless/ath/wil6210/txrx.c
+++ b/drivers/net/wireless/ath/wil6210/txrx.c
@@ -37,6 +37,10 @@
 module_param(rx_align_2, bool, 0444);
 MODULE_PARM_DESC(rx_align_2, " align Rx buffers on 4*n+2, default - no");
 
+bool rx_large_buf;
+module_param(rx_large_buf, bool, 0444);
+MODULE_PARM_DESC(rx_large_buf, " allocate 8KB RX buffers, default - no");
+
 static inline uint wil_rx_snaplen(void)
 {
 	return rx_align_2 ? 6 : 0;
@@ -255,7 +259,7 @@ static int wil_vring_alloc_skb(struct wil6210_priv *wil, struct vring *vring,
 			       u32 i, int headroom)
 {
 	struct device *dev = wil_to_dev(wil);
-	unsigned int sz = mtu_max + ETH_HLEN + wil_rx_snaplen();
+	unsigned int sz = wil->rx_buf_len + ETH_HLEN + wil_rx_snaplen();
 	struct vring_rx_desc dd, *d = &dd;
 	volatile struct vring_rx_desc *_d = &vring->va[i].rx;
 	dma_addr_t pa;
@@ -419,7 +423,7 @@ static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil,
 	struct sk_buff *skb;
 	dma_addr_t pa;
 	unsigned int snaplen = wil_rx_snaplen();
-	unsigned int sz = mtu_max + ETH_HLEN + snaplen;
+	unsigned int sz = wil->rx_buf_len + ETH_HLEN + snaplen;
 	u16 dmalen;
 	u8 ftype;
 	int cid;
@@ -780,6 +784,20 @@ void wil_rx_handle(struct wil6210_priv *wil, int *quota)
 	wil_rx_refill(wil, v->size);
 }
 
+static void wil_rx_buf_len_init(struct wil6210_priv *wil)
+{
+	wil->rx_buf_len = rx_large_buf ?
+		WIL_MAX_ETH_MTU : TXRX_BUF_LEN_DEFAULT - WIL_MAX_MPDU_OVERHEAD;
+	if (mtu_max > wil->rx_buf_len) {
+		/* do not allow RX buffers to be smaller than mtu_max, for
+		 * backward compatibility (mtu_max parameter was also used
+		 * to support receiving large packets)
+		 */
+		wil_info(wil, "Override RX buffer to mtu_max(%d)\n", mtu_max);
+		wil->rx_buf_len = mtu_max;
+	}
+}
+
 int wil_rx_init(struct wil6210_priv *wil, u16 size)
 {
 	struct vring *vring = &wil->vring_rx;
@@ -792,6 +810,8 @@ int wil_rx_init(struct wil6210_priv *wil, u16 size)
 		return -EINVAL;
 	}
 
+	wil_rx_buf_len_init(wil);
+
 	vring->size = size;
 	rc = wil_vring_alloc(wil, vring);
 	if (rc)
diff --git a/drivers/net/wireless/ath/wil6210/wil6210.h b/drivers/net/wireless/ath/wil6210/wil6210.h
index 9cedc2d..2af4a64 100644
--- a/drivers/net/wireless/ath/wil6210/wil6210.h
+++ b/drivers/net/wireless/ath/wil6210/wil6210.h
@@ -32,6 +32,7 @@
 extern int agg_wsize;
 extern u32 vring_idle_trsh;
 extern bool rx_align_2;
+extern bool rx_large_buf;
 extern bool debug_fw;
 extern bool disable_ap_sme;
 
@@ -656,6 +657,7 @@ struct wil6210_priv {
 	struct work_struct probe_client_worker;
 	/* DMA related */
 	struct vring vring_rx;
+	unsigned int rx_buf_len;
 	struct vring vring_tx[WIL6210_MAX_TX_RINGS];
 	struct vring_tx_data vring_tx_data[WIL6210_MAX_TX_RINGS];
 	u8 vring2cid_tid[WIL6210_MAX_TX_RINGS][2]; /* [0] - CID, [1] - TID */
diff --git a/drivers/net/wireless/ath/wil6210/wmi.c b/drivers/net/wireless/ath/wil6210/wmi.c
index 9255c47..e6c249d 100644
--- a/drivers/net/wireless/ath/wil6210/wmi.c
+++ b/drivers/net/wireless/ath/wil6210/wmi.c
@@ -1398,7 +1398,8 @@ int wmi_rx_chain_add(struct wil6210_priv *wil, struct vring *vring)
 	struct wmi_cfg_rx_chain_cmd cmd = {
 		.action = WMI_RX_CHAIN_ADD,
 		.rx_sw_ring = {
-			.max_mpdu_size = cpu_to_le16(wil_mtu2macbuf(mtu_max)),
+			.max_mpdu_size = cpu_to_le16(
+				wil_mtu2macbuf(wil->rx_buf_len)),
 			.ring_mem_base = cpu_to_le64(vring->pa),
 			.ring_size = cpu_to_le16(vring->size),
 		},
-- 
1.9.1