Oh yeah, my Thinkpad Tablet 10 is finally sleeping, or rather it does a „suspend-to-idle“. Whow! That was some major pain. Today I first found a nice patch that is supposed to help with the nasty Baytrail MMC timeouts:

http://www.spinics.net/lists/linux-mmc/msg36309.html

Update: It could be necessary to add another two patches especially for the brcmfmac WiFi:

http://marc.info/?l=linux-mmc&m=143023247221784

[ Kudos to Adrian Hunter who is also very supportive, thanks! ]

While putting that into my current kernel 4.5.2 I also got rid of more drivers, especially drivers that do not currently work, like the sound driver. I am not sure what it was but either the above patch, that enables some mysterious settings in the CPU, or the missing sound driver did the trick! I can now „freeze“ the machine and it will come back to life either using the power button or the windows home button. This is excellent!

If I now can find a way to get battery readings I would be really happy with this machine. Any more drivers will have to come later, like the cameras, fingerprint, NFC or sound. Concerning sound since I have the Bluetooth working I can use a Bluetooth A2DP device like my Zik or some other like a Bose Soundlink Mini (very good speakers!) or a simple Bluetooth headphone adapter I got from China several years ago – very nice in combination with my Bose Triport in-ears.

Update, June 20th: I am pretty sure now that the Baytrail SST sound driver prevents sleeping or rather freezes the system while trying to go to sleep.