drivers:misc: ti-st: fix hci-ll on wake_ind collision

Where file-transfer stops/pauses in between, is
result of a HCI-LL anamoly in ST LL driver.
ST LL did not copy the contents of WaitQ into the TxQ, when a WAKEUP_IND
collision happened.
Make also sure, that the copying mechanism is safe, by wrapping it around
spin locks inside st_int_recv().
This was easily reproduced when the sleep timeout was reduced to 100ms
for HCI-LL.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
index dd2c879faff696abad2e6c01fb2be78602da0caf..f0d24d852078d87f967fadcffee4fa420eb702a0 100644 (file)
--- a/drivers/misc/ti-st/st_core.c
+++ b/drivers/misc/ti-st/st_core.c
@@ -236,6 +236,7 @@ void st_int_recv(void *disc_data,
        int len = 0, type = 0;
        unsigned char *plen;
        struct st_data_s *st_gdata = (struct st_data_s *)disc_data;
+       unsigned long flags;
 
        ptr = (char *)data;
        /* tty_receive sent null ? */
@@ -248,6 +249,7 @@ void st_int_recv(void *disc_data,
                   "rx_count %ld", count, st_gdata->rx_state,
                   st_gdata->rx_count);
 
+       spin_lock_irqsave(&st_gdata->lock, flags);
        /* Decode received bytes here */
        while (count) {
                if (st_gdata->rx_count) {
@@ -308,13 +310,25 @@ void st_int_recv(void *disc_data,
                         * sleep state received --
                         */
                        st_ll_sleep_state(st_gdata, *ptr);
+                       /* if WAKEUP_IND collides copy from waitq to txq
+                        * and assume chip awake
+                        */
+                       spin_unlock_irqrestore(&st_gdata->lock, flags);
+                       if (st_ll_getstate(st_gdata) == ST_LL_AWAKE)
+                               st_wakeup_ack(st_gdata, LL_WAKE_UP_ACK);
+                       spin_lock_irqsave(&st_gdata->lock, flags);
+
                        ptr++;
                        count--;
                        continue;
                case LL_WAKE_UP_ACK:
                        pr_debug("PM packet");
+
+                       spin_unlock_irqrestore(&st_gdata->lock, flags);
                        /* wake up ack received */
                        st_wakeup_ack(st_gdata, *ptr);
+                       spin_lock_irqsave(&st_gdata->lock, flags);
+
                        ptr++;
                        count--;
                        continue;
@@ -337,6 +351,7 @@ void st_int_recv(void *disc_data,
                ptr++;
                count--;
        }
+       spin_unlock_irqrestore(&st_gdata->lock, flags);
        pr_debug("done %s", __func__);
        return;
 }