Lately, I’ve been trying to get the GPD Win to run Antergos + Xfce4. Through an intensive process detailed here and here, the device is almost 100% functional when it comes to hardware. However, there is one problem I’ve been having that I’m at a loss for.

The SD Card reader doesn’t work.

Keep in mind, that I’m running a modified 4.12-rc5 kernel (which can be found in the third link above) and the SD Host is recognized with lspci as:
00:12.0 SD Host controller: Intel Corporation Atom/Celeron/Pentium Processor x5-E8000/J3xxx/N3xxx Series SD Controller (rev 20).

And in dsmesg I found one reference to the external SD card that’s of interest:
mmc1: error -110 whilst initializing SD card.

The SD card in question works; in fact, I’ve tried four different SD cards, each of which work elsewhere but do nothing on Linux. And it worked when it was originally running Windows 10. Any suggestions?