From 77ed74da26f50fa28471571ee7a2251b77526d84 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Sat, 30 Sep 2006 17:18:59 +0200 Subject: [PATCH] [PATCH] i2c: Prevent deadlock on i2c client registration Delay the call to adapter->client_register() until after we are certain that the client registration is a success. At this point the client is fully initialized and we no longer hold the adapter->clist mutex, so this should prevent the deadlocks if the client_register() callback needs to take that mutex too, as is the case for the bttv driver. This fixes bug #7234. Signed-off-by: Jean Delvare Signed-off-by: Linus Torvalds --- drivers/i2c/i2c-core.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 01233f0f7771..7ca81f42d14b 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -420,14 +420,6 @@ int i2c_attach_client(struct i2c_client *client) } list_add_tail(&client->list,&adapter->clients); - if (adapter->client_register) { - if (adapter->client_register(client)) { - dev_dbg(&adapter->dev, "client_register " - "failed for client [%s] at 0x%02x\n", - client->name, client->addr); - } - } - client->usage_count = 0; client->dev.parent = &client->adapter->dev; @@ -445,10 +437,17 @@ int i2c_attach_client(struct i2c_client *client) res = device_create_file(&client->dev, &dev_attr_client_name); if (res) goto out_unregister; - -out_unlock: mutex_unlock(&adapter->clist_lock); - return res; + + if (adapter->client_register) { + if (adapter->client_register(client)) { + dev_dbg(&adapter->dev, "client_register " + "failed for client [%s] at 0x%02x\n", + client->name, client->addr); + } + } + + return 0; out_unregister: init_completion(&client->released); /* Needed? */ @@ -458,7 +457,9 @@ out_list: list_del(&client->list); dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x " "(%d)\n", client->name, client->addr, res); - goto out_unlock; +out_unlock: + mutex_unlock(&adapter->clist_lock); + return res; } -- 2.30.2