From c30c9b15187e977ab5928f7276e9dfcd8d6f9460 Mon Sep 17 00:00:00 2001 From: David Fries Date: Wed, 15 Oct 2008 22:04:38 -0700 Subject: W1: fix deadlocks and remove w1_control_thread w1_control_thread was removed which would wake up every second and process newly registered family codes and complete some final cleanup for a removed master. Those routines were moved to the threads that were previously requesting those operations. A new function w1_reconnect_slaves takes care of reconnecting existing slave devices when a new family code is registered or removed. The removal case was missing and would cause a deadlock waiting for the family code reference count to decrease, which will now happen. A problem with registering a family code was fixed. A slave device would be unattached if it wasn't yet claimed, then attached at the end of the list, two unclaimed slaves would cause an infinite loop. The struct w1_bus_master.search now takes a pointer to the struct w1_master device to avoid searching for it, which would have caused a lock ordering deadlock with the removal of w1_control_thread. Signed-off-by: David Fries Signed-off-by: Evgeniy Polyakov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/w1/w1.h | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'drivers/w1/w1.h') diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h index f1df5343f4a..13e0ea880bf 100644 --- a/drivers/w1/w1.h +++ b/drivers/w1/w1.h @@ -77,7 +77,7 @@ struct w1_slave struct completion released; }; -typedef void (* w1_slave_found_callback)(void *, u64); +typedef void (*w1_slave_found_callback)(struct w1_master *, u64); /** @@ -142,12 +142,14 @@ struct w1_bus_master */ u8 (*reset_bus)(void *); - /** Really nice hardware can handles the different types of ROM search */ - void (*search)(void *, u8, w1_slave_found_callback); + /** Really nice hardware can handles the different types of ROM search + * w1_master* is passed to the slave found callback. + */ + void (*search)(void *, struct w1_master *, + u8, w1_slave_found_callback); }; #define W1_MASTER_NEED_EXIT 0 -#define W1_MASTER_NEED_RECONNECT 1 struct w1_master { @@ -181,12 +183,21 @@ struct w1_master }; int w1_create_master_attributes(struct w1_master *); +void w1_destroy_master_attributes(struct w1_master *master); void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb); void w1_search_devices(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb); struct w1_slave *w1_search_slave(struct w1_reg_num *id); void w1_search_process(struct w1_master *dev, u8 search_type); struct w1_master *w1_search_master_id(u32 id); +/* Disconnect and reconnect devices in the given family. Used for finding + * unclaimed devices after a family has been registered or releasing devices + * after a family has been unregistered. Set attach to 1 when a new family + * has just been registered, to 0 when it has been unregistered. + */ +void w1_reconnect_slaves(struct w1_family *f, int attach); +void w1_slave_detach(struct w1_slave *sl); + u8 w1_triplet(struct w1_master *dev, int bdir); void w1_write_8(struct w1_master *, u8); int w1_reset_bus(struct w1_master *); -- cgit v1.2.3-18-g5258