Merge branch 'char-misc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

* 'char-misc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  isl29020: Remove a redundant semi-colon from return statement
  BMP085: Remove redundant semi-colon from return statement
  drivers:misc: ti-st: DEBUG uart, baud rate mods
  drivers:misc: ti-st: flush UART upon fw failure
  drivers:misc: ti-st: protect registrations
  char_dev.c: fix up some whitespace errors
  s390: tape_class.h: remove kobj_map.h inclusion
  misc: ad525x_dpot: Add support for SPI module device table matching

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 ba168a7d54d4..2b62232c2c6a 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 ");