PORTS Forum
Ports and Interfaces => USB => Topic started by: danwaqar on January 27, 2021, 01:15:55 pm
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http://ww1.microchip.com/downloads/en/DeviceDoc/00001692C.pdf
the above hub is part of a host to which my usb 2.0 device(uses usb3320 phy) is connecting.
my device works with all other standard hosts.
but this mentioned linux based host shows unique problem where it has an internal audio device connected to the same hub (bus sharing). using a hardware analyser i am seeing packets destined to the endpoint which are non-existent in my device. once i ask the host to disable the internal audio device with those endpoints my device starts working with the host but when this is internal device is enabled my device stops working.
so my argument is that i shouldn't be seeing those packets in first place and while i am seeing what should i do at device end to address this?
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No your device shouldn't be seeing those packets. Has the host somehow assigned the same bus address to both devices?
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no it looks like the address is different but then those packets shouldnt be here. this is the capture from hardware analyser showing the address and endpoint in the trace
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If the address doesn't match, the device should ignore it. That's the reason for having addresses.
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can you elaborate more how i can add this functionality in my device, i ignore the address or the specific endpoint?
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The mechanism for filtering by address is specific to the device hardware/firmware. See your device's data sheet for details.
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Mmm, hubs usually transmit upstream data to all downstream ports.
Is this what you're talking about?
Your hardware should be ignoring anything not on its own address.
Usually for hardware debugging you want to use a host controller with nothing else connected (just so it's quieter).