1 files changed, 14 insertions, 4 deletions

diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
index ba168a7d54d..2b62232c2c6 100644
--- a/drivers/misc/ti-st/st_core.c
+++ b/drivers/misc/ti-st/st_core.c
@@ -137,6 +137,8 @@ void st_send_frame(unsigned char chnl_id, struct st_data_s *st_gdata)
  * st_reg_complete -
  * to call registration complete callbacks
  * of all protocol stack drivers
+ * This function is being called with spin lock held, protocol drivers are
+ * only expected to complete their waits and do nothing more than that.
  */
 void st_reg_complete(struct st_data_s *st_gdata, char err)
 {
@@ -538,11 +540,12 @@ long st_register(struct st_proto_s *new_proto)
                 set_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
                 st_recv = st_kim_recv;
 
+                /* enable the ST LL - to set default chip state */
+                st_ll_enable(st_gdata);
+
                 /* release lock previously held - re-locked below */
                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 
-                /* enable the ST LL - to set default chip state */
-                st_ll_enable(st_gdata);
                 /* this may take a while to complete
                  * since it involves BT fw download
                  */
@@ -553,10 +556,13 @@ long st_register(struct st_proto_s *new_proto)
                             (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
                                 pr_err(" KIM failure complete callback ");
                                 st_reg_complete(st_gdata, err);
+                                clear_bit(ST_REG_PENDING, &st_gdata->st_state);
                         }
                         return -EINVAL;
                 }
 
+                spin_lock_irqsave(&st_gdata->lock, flags);
+
                 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
                 st_recv = st_int_recv;
 
@@ -576,10 +582,10 @@ long st_register(struct st_proto_s *new_proto)
                 if (st_gdata->is_registered[new_proto->chnl_id] == true) {
                         pr_err(" proto %d already registered ",
                                    new_proto->chnl_id);
+                        spin_unlock_irqrestore(&st_gdata->lock, flags);
                         return -EALREADY;
                 }
 
-                spin_lock_irqsave(&st_gdata->lock, flags);
                 add_channel_to_table(st_gdata, new_proto);
                 st_gdata->protos_registered++;
                 new_proto->write = st_write;
@@ -619,7 +625,7 @@ long st_unregister(struct st_proto_s *proto)
 
         spin_lock_irqsave(&st_gdata->lock, flags);
 
-        if (st_gdata->list[proto->chnl_id] == NULL) {
+        if (st_gdata->is_registered[proto->chnl_id] == false) {
                 pr_err(" chnl_id %d not registered", proto->chnl_id);
                 spin_unlock_irqrestore(&st_gdata->lock, flags);
                 return -EPROTONOSUPPORT;
@@ -629,6 +635,10 @@ long st_unregister(struct st_proto_s *proto)
         remove_channel_from_table(st_gdata, proto);
         spin_unlock_irqrestore(&st_gdata->lock, flags);
 
+        /* paranoid check */
+        if (st_gdata->protos_registered < ST_EMPTY)
+                st_gdata->protos_registered = ST_EMPTY;
+
         if ((st_gdata->protos_registered == ST_EMPTY) &&
             (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
                 pr_info(" all chnl_ids unregistered ");