Here is the IRC discussion with Jolla (rainemak) about DP Alt mode:
17:06:59 @Linux_ Hi, will the Jolla Phone support USB-C DisplayPort Alt Mode?
17:07:23 @rainemak Linux_, afaiu now it does not
17:09:40 @Linux_ Okay, what are the main challenges implementing DP Alt Mode?
17:10:56 @rainemak Linux_, I don’t have all the details… but I think ran out of USB lines
17:11:01 @rainemak we ran
17:11:56 @attah (But i still think DP alt mode would be nice for if and when that happens)
17:13:08 @attah Ran out of USB lanes on what?
17:13:16 @rainemak attah, hw
17:13:34 @rainemak sw missing as well
17:14:17 @rainemak attah, The Other Half might have reserved some
17:14:19 @rainemak 
17:14:43 @attah Interesting
17:17:10 @rainemak attah, that’s one aspect
17:17:21 @Linux_ Would it be possible to cut lines for The Other Half and bring DP Alt with a custom sub/charging board? I.e. does the SoC and mainboard itself support DP Alt Mode?
17:18:08 @rainemak Linux_, I don’t think so
17:18:29 @Linux_ 
Additionally:
17:11:33 @attah SFOS has no support for outputting to a second monitor on the SW side either, right?
17:11:51 @rainemak attah, correct → that requires a bit of work
17:13:42 @Linux_ attah, Maybe but I think it’s important for tinkering with other distros and also with SFOS in the future.
Source IRC meeting log 2026-04-09 : #sailfishos-meeting log
Edit: moved misplaced sentence