How was the guy who had xdaliclock running on his Kindle handling this, I wonder? I think there was ghosting. Does that come from not doing any explicit refreshes at all, or doing the "low cost" kind rapidly?
Somewhere I saw a reference to writing numbers to magic files in /sys to get different refresh operations. Is this the route a user app should take if it wants to decide when the screen gets updated, as opposed to delegating it to another layer like Qt?
Do you know how much of the e-ink fb driver in Kindle is mainline kernel and how much is custom?