According to this thread [1], these two patches [2][3] should fix the issue. Can you backport to Wheezy kernel? Cheers [1] https://bbs.archlinux.org/viewtopic.php?id=139270 [2] http://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=commitdiff;h=62e2c102cc1d2600381410c089ca9a37359577d2 [3] http://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=commitdiff;h=5c17ddc4a047c59638c7eb8537aa887a1ddb9b0b