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>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
index dd2c879faff6..f0d24d852078 100644
--- 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;
 }