i2c: Clear i2c_adapter.dev on adapter removal

Clear i2c_adapter.dev on adapter removal. This makes it possible to
re-add the adapter at a later point, which some drivers
(i2c-amd756-s4882, i2c-nforce2-s4985) actually do.

This fixes a bug reported by John Stultz here:
  http://lkml.org/lkml/2008/7/15/720
and by Ingo Molar there:
  http://lkml.org/lkml/2008/7/16/78

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 0a79f7661017..7608df83d6d1 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -654,6 +654,10 @@ int i2c_del_adapter(struct i2c_adapter *adap)
 
         dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
 
+        /* Clear the device structure in case this adapter is ever going to be
+           added again */
+        memset(&adap->dev, 0, sizeof(adap->dev));
+
  out_unlock:
         mutex_unlock(&core_lock);
         return res;