I also tried the trans mmc which could reproduce this bug on CID 201401-14493, on another 14.04.1 system.
This mmc could be read and written data normally. dmesg-working-trans.log is the dmesg collected by that 14.04.1 system for your reference. ** Attachment added: "dmesg-working-trans.log" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1397285/+attachment/4376861/+files/dmesg-working-trans.log -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1397285 Title: O2 Micro cardreader [1217:8621] could not read mmc cards To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1397285/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs