On Wed, 2023-09-27 at 17:52 +0200, Pavel Machek wrote: > Hi! > > > > I'm having some fun with usb host. Good news is it works with > > > externally powered hub... after a while. I get some error > > > messages > > > about inability to go host mode, but with enough patience it > > > eventually does enter host mode and I see my keyboard/mouse. > > > > > > And usually in that process, one of my cpu cores disappear. top > > > no > > > longer shows 2 cores, and I was wondering for a while if d4 is > > > single-core system. It is not, my two cores are back after > > > reboot. > > > > > > That's with 6.1.9 kernel from leste. Ideas how to debug this > > > would be > > > welcome. (Do you use usb host?) > > > > You are using a "proper" non-standard usb micro-b cable that > > grounds > > the id pin, right? > > Yes. > > > If not, try with one of those as it allows the hardware to do what > > it's > > supposed to do. > > > > And presumably you don't have a hacked usb hub that feeds back the > > vbus to your phone, right? > > Do have hacked hub. Or more precisely, have device that needs > external > power (spinning rust), and hub passes it back to the device. > > I'll retry with a keyboard... but I recall it behaved funny with > that, too. > > > If you have, that should not be used as the pmic can feed vbus. > > Well, my plan was to use it as a desktop, and external power is > useful > that as Droid battery is not that big. > > Best regards, > Pavel
I use usb host quite a bit with xt875, mostly to have a keyboard. I have noted that several hubs i have don't work reliably, im not sure why. Its possible that they use or request too mutch power from the port as cpcap has a pretty small vbus out limit. All my regular otg adapters work fine however. I also have a powered hub that works quite well, its item 373697032160 on ebay
