I applied a number of patches (commit # as below) on 12.04's lts-backport-quantal kernel, and it can fix the problem.
92fdf89aa95de32dba1cb44fe7f5c54824b4b2c4 8a37c65df9dcbd1c891df2b4a94157999b654841 c49170742d6928b16fb3839b47a94cc41630dbe0 fda4b25c55a59ba12378e4b9e4553f6ea57d802d ce3cf821a31f9824eda788cbd3e710d8047e82df fd64ca8a9d9d7e92fc81fe0b23dcf324246fd356 86504672f7d79986a8ef618fb120044220e3d1eb f3728734ba78310525bf4a361c7787c7c6fa5d40 910308802c528f8afe864b694d5456fedd0bb18f af7912e57316caa1b705f06b03592cec0737cb36 efd4e418f2bb8a8b21f96fd44e775eaf6dd55905 9e05b2f49eb9484e857e9b6c70dea3bbbe564290
I applied a number of patches (commit # as below) on 12.04's lts-backport- quantal kernel, and it can fix the problem.
92fdf89aa95de32 dba1cb44fe7f5c5 4824b4b2c4 c891df2b4a94157 999b654841 16fb3839b47a94c c41630dbe0 12378e4b9e4553f 6ea57d802d 4eda788cbd3e710 d8047e82df 2fc81fe0b23dcf3 24246fd356 6a8ef618fb12004 4220e3d1eb 525bf4a361c7787 c7c6fa5d40 afe864b694d5456 fedd0bb18f 1b705f06b03592c ec0737cb36 b21f96fd44e775e af6dd55905 e857e9b6c70dea3 bbbe564290
8a37c65df9dcbd1
c49170742d6928b
fda4b25c55a59ba
ce3cf821a31f982
fd64ca8a9d9d7e9
86504672f7d7998
f3728734ba78310
910308802c528f8
af7912e57316caa
efd4e418f2bb8a8
9e05b2f49eb9484