mwifiex: fix driver init failure under memory pressure

64k Tx and Rx buffers are allocated during driver initialization
for SDIO level data aggregations. When host is under memory
pressure situation, kzalloc() request for 64k may fail.

We will try allocating 32k buffers and disable our rx single port
aggreagation feature in this situation.

If the allocation still fails, we will disable our sdio multport
aggregation feature as well. In this way, we will transmit and
receive packets one by one, thus reduce the demand for big
memory.
Signed-off-by: Xinming Hu <huxm@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/mwifiex/main.h

@@ -860,6 +860,8 @@ struct mwifiex_adapter {
 	u8 more_task_flag;
 	u16 tx_buf_size;
 	u16 curr_tx_buf_size;
+	/* sdio single port rx aggregation capability */
+	bool host_disable_sdio_rx_aggr;
 	bool sdio_rx_aggr_enable;
 	u16 sdio_rx_block_size;
 	u32 ioport;

drivers/net/wireless/mwifiex/sdio.c

@@ -2058,16 +2058,26 @@ static int mwifiex_init_sdio(struct mwifiex_adapter *adapter)
 	ret = mwifiex_alloc_sdio_mpa_buffers(adapter,
 					     card->mp_tx_agg_buf_size,
 					     card->mp_rx_agg_buf_size);
+
+	/* Allocate 32k MPA Tx/Rx buffers if 64k memory allocation fails */
+	if (ret && (card->mp_tx_agg_buf_size == MWIFIEX_MP_AGGR_BUF_SIZE_MAX ||
+		    card->mp_rx_agg_buf_size == MWIFIEX_MP_AGGR_BUF_SIZE_MAX)) {
+		/* Disable rx single port aggregation */
+		adapter->host_disable_sdio_rx_aggr = true;
+
+		ret = mwifiex_alloc_sdio_mpa_buffers
+			(adapter, MWIFIEX_MP_AGGR_BUF_SIZE_32K,
+			 MWIFIEX_MP_AGGR_BUF_SIZE_32K);
 		if (ret) {
-		mwifiex_dbg(adapter, ERROR,
-			    "failed to alloc sdio mp-a buffers\n");
-		kfree(card->mp_regs);
-		return -1;
+			/* Disable multi port aggregation */
+			card->mpa_tx.enabled = 0;
+			card->mpa_rx.enabled = 0;
+		}
 	}
 
 	adapter->auto_tdls = card->can_auto_tdls;
 	adapter->ext_scan = card->can_ext_scan;
-	return ret;
+	return 0;
 }
 
 /*

drivers/net/wireless/mwifiex/sta_cmd.c

@@ -2125,7 +2125,8 @@ int mwifiex_sta_init_cmd(struct mwifiex_private *priv, u8 first_sta, bool init)
 
 		/** Set SDIO Single Port RX Aggr Info */
 		if (priv->adapter->iface_type == MWIFIEX_SDIO &&
-		    ISSUPP_SDIO_SPA_ENABLED(priv->adapter->fw_cap_info)) {
+		    ISSUPP_SDIO_SPA_ENABLED(priv->adapter->fw_cap_info) &&
+		    !priv->adapter->host_disable_sdio_rx_aggr) {
 			sdio_sp_rx_aggr_enable = true;
 			ret = mwifiex_send_cmd(priv,
 					       HostCmd_CMD_SDIO_SP_RX_AGGR_CFG,