Comment 46 for bug 1178131

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StefanF (stefan) wrote : Re: 14e4:16bc SD card slot not working on Acer Aspire One 756

The problem is caused by a combination of three bugs in the computer:

1) The card reader does not support L1 although this is a mandatory feature in the PCIe specification (see http://wireless.kernel.org/en/users/Documentation/ASPM).
2) The BIOS enables L1 although the hardware does not support it.
3) The BIOS dictates that ASPM must be disabled but it does not support _OSC control, so the Linux Kernel cannot disable ASPM during boot.

Workaround: Place the command "setpci -s 00:1c.2 0x50.B=0x41" into /etc/rc.local and create a new file /etc/apm/resume.d/21aspm with the same command.