Fixed bug #429.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/branches/stable_2.4.x@6217 35acf78f-673a-0410-8e92-d51de3d6d3f4
Fixed bug #428.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/branches/stable_2.4.x@6218 35acf78f-673a-0410-8e92-d51de3d6d3f4