mwifiex: more_task flag for main_process

This patch handles a corner case where TX packet would remain in
driver queue till next packet comes in.
Here is sequence:
1. TX packet is queued via hard_start_xmit and main_work is queued
2. SDIO interrupt comes in which directly call mwifiex_main_process.
This starts executing main superloop.
3. Now work from step1 is scheduled but at first check itself it sees
mwifiex_processing is set and exits.
4. Now if superloop from step2 has passed TX processing part of superloop
this packet would remain in queue until next packet/command/SDIO interrupt
arrives and queues main_work.

This patch fixes this corner case by defining more_task flag which is set when
mwifiex_processing is found to be true. At end of superloop we again check if
more_task flag is set and if set, execute superloop again.

Signed-off-by: Shengzhen Li <szli@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>
Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/mwifiex/main.c

@@ -190,14 +190,16 @@ int mwifiex_main_process(struct mwifiex_adapter *adapter)
 
 	/* Check if already processing */
 	if (adapter->mwifiex_processing) {
+		adapter->more_task_flag = true;
 		spin_unlock_irqrestore(&adapter->main_proc_lock, flags);
 		goto exit_main_proc;
 	} else {
 		adapter->mwifiex_processing = true;
-		spin_unlock_irqrestore(&adapter->main_proc_lock, flags);
 	}
 process_start:
 	do {
+		adapter->more_task_flag = false;
+		spin_unlock_irqrestore(&adapter->main_proc_lock, flags);
 		if ((adapter->hw_status == MWIFIEX_HW_STATUS_CLOSING) ||
 		    (adapter->hw_status == MWIFIEX_HW_STATUS_NOT_READY))
 			break;
@@ -238,6 +240,7 @@ process_start:
 			adapter->pm_wakeup_fw_try = true;
 			mod_timer(&adapter->wakeup_timer, jiffies + (HZ*3));
 			adapter->if_ops.wakeup(adapter);
+			spin_lock_irqsave(&adapter->main_proc_lock, flags);
 			continue;
 		}
 
@@ -295,8 +298,10 @@ process_start:
 		if ((adapter->ps_state == PS_STATE_SLEEP) ||
 		    (adapter->ps_state == PS_STATE_PRE_SLEEP) ||
 		    (adapter->ps_state == PS_STATE_SLEEP_CFM) ||
-		    adapter->tx_lock_flag)
+		    adapter->tx_lock_flag){
+			spin_lock_irqsave(&adapter->main_proc_lock, flags);
 			continue;
+		}
 
 		if (!adapter->cmd_sent && !adapter->curr_cmd) {
 			if (mwifiex_exec_next_cmd(adapter) == -1) {
@@ -330,15 +335,12 @@ process_start:
 			}
 			break;
 		}
+		spin_lock_irqsave(&adapter->main_proc_lock, flags);
 	} while (true);
 
 	spin_lock_irqsave(&adapter->main_proc_lock, flags);
-	if (!adapter->delay_main_work &&
-	    (adapter->int_status || IS_CARD_RX_RCVD(adapter))) {
-		spin_unlock_irqrestore(&adapter->main_proc_lock, flags);
+	if (adapter->more_task_flag)
 		goto process_start;
-	}
-
 	adapter->mwifiex_processing = false;
 	spin_unlock_irqrestore(&adapter->main_proc_lock, flags);
 

drivers/net/wireless/mwifiex/main.h

@@ -774,6 +774,7 @@ struct mwifiex_adapter {
 	/* spin lock for main process */
 	spinlock_t main_proc_lock;
 	u32 mwifiex_processing;
+	u8 more_task_flag;
 	u16 tx_buf_size;
 	u16 curr_tx_buf_size;
 	u32 ioport;