droid4 -- weird behaviour when attempting to use usb host
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?)
Best regards,
Pavel
Quoted 7 lines · Pavel Machek
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.
Quoted 6 lines
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?
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?
If you have, that should not be used as the pmic can feed vbus.
Regards,
Tony
Hi!
Quoted 9 lines
Quoted 9 lines
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.
Quoted 5 lines
Quoted 2 lines
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.
Quoted 5 lines
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.
Quoted 1 line
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
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Quoted 38 lines · Pavel Machek
Hi!
Quoted 12 lines
Quoted 12 lines
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.Quoted 7 lines
Quoted 3 lines
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.
Quoted 6 lines
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.
Quoted 8 lines
Quoted 1 line
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
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