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Re: Tracing lost USB bytes

On 05/09/17 13:48, Edgar Fuß wrote:
Sounds like a data-toggle problem.
OK, thanks. I first had to research what that is.

Hard to debug w/o a bus trace, because the host controller handles this.
I'll try to get hold of a hardware tracer then.

Would be to know host controller type when looking at this.
OHCI, if I read my dmesg correctly:

Supermicro H8SCM (1234567890)
mainbus0 (root)
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o space, memory space enabled, rd/line, rd/mult, wr/inv ok
ohci0 at pci0 dev 18 function 0: vendor 0x1002 product 0x4397 (rev. 0x00)
ohci0: interrupting at ioapic0 pin 16
ohci0: OHCI version 1.0, legacy support
usb0 at ohci0: USB revision 1.0
uhub0 at usb0: vendor 0x1002 OHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 3 ports with 3 removable, self powered
ugen0 at uhub0 port 1
ugen0: Phoenixtec Power USB Cable (V2.00), rev 1.00/0.06, addr 2
ugen1 at uhub0 port 2
ugen1: Phoenixtec Power USB Cable (V2.00), rev 1.00/0.06, addr 3

Interrupt transfers are very likely to lose data if not serviced fast enough which is very likely with ugen access.


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