Re: cannot reliably detect USB device

Kay Sievers
2009-01-03T22:08:01Z

On Thu, Jan 1, 2009 at 18:44, Andreas Mohr <andi@lisas.de> wrote:
>> > > I have a pl2303 USB-RS232 converter that cannot be reliably
>> > > detected.
>> >
>> > Faulty hardware? Flaky cables? Bad connections? If this is
>> > reproducable for the same device on multiple machines, I'd just go buy
>> > a
>> > new device :)
>>
>> I decided to give it a last try before planning a replacement - then I
>> find that /dev/ttyUSB0 could be created if I enlarge the retry times.
>>
>> It could take 10 seconds to get a valid response. It must go crazy.
>
> Detected _instantly_ on 2.6.28 here:
>
> [59750.560209] usb 1-1: USB disconnect, address 5
> [59750.561888] pl2303 ttyUSB0: pl2303 converter now disconnected from ttyUSB0
> [59750.561970] pl2303 1-1:1.0: device disconnected
> [59752.904108] usb 1-1: new full speed USB device using uhci_hcd and address 6
> [59753.059546] usb 1-1: configuration #1 chosen from 1 choice
> [59753.061460] pl2303 1-1:1.0: pl2303 converter detected
> [59753.114738] usb 1-1: pl2303 converter now attached to ttyUSB0
>
> (the 3-second delay basically was me waiting before reinserting)
>
>
> Bus 001 Device 006: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
>
> Label: "GMUS-03 USB Serial Adapter"
>
> Detection test only, _not_ used for actual serial communication currently...
>
>
> But there are more PL2303 adapters than flies on this planet,
> thus someone else also has some input on this?

Mine works fine with today's Linux git tree:
usb 1-2.2: new full speed USB device using uhci_hcd and address 11
usb 1-2.2: configuration #1 chosen from 1 choice
pl2303 1-2.2:1.0: pl2303 converter detected
usb 1-2.2: pl2303 converter now attached to ttyUSB0

Kay