Date: Thu, 10 Oct 2013 01:09:51 -0700 From: aseem jolly <aseem.jolly@gmail.com> To: Hans Petter Selasky <hps@bitfrost.no> Cc: freebsd-usb@freebsd.org Subject: Re: USB device configuration Message-ID: <CAC%2BxDdjn76ORuPOJB-_htm=xdLtL9URb97NPwCdFrAGtSpr4Zw@mail.gmail.com> In-Reply-To: <52565C69.905@bitfrost.no> References: <1381274499940-5850403.post@n5.nabble.com> <5254FD72.2050507@bitfrost.no> <1381342263797-5850596.post@n5.nabble.com> <525649BB.2060906@bitfrost.no> <1381390376377-5850751.post@n5.nabble.com> <52565C69.905@bitfrost.no>
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The device I am talking about has one configuration only. I was planning to
take bus trace or usbdump since I am not seeing it again so I don't think
that would help now.
On Thu, Oct 10, 2013 at 12:51 AM, Hans Petter Selasky <hps@bitfrost.no>wrote:
> Hi,
>
>
> On 10/10/13 09:32, aseem.jolly wrote:
>
>> It is allowed to set the configuration multiple times. Refer to USB
>>> 2.0 specification.
>>>
>> >
>
>> In what possible scenario would we want to set the configuration again? I
>> know USB 2.0 specification allows it. I have also tried to modify the code
>> and have sent SET_CONFIGURATION request to the device multiple times, and
>> device didn't report any error.
>>
>
> Some devices have multiple configurations with different interfaces, which
> the application selects depending on the use-case. Many devices only have
> one configuration.
>
>
>> Or do you mean different configurations of a device, if a device supports
>> more that one configuration?
>>
>>
>> Is this making a difference for you?
>>>
>> I have scene a case in which we were unable to attach the umass driver to
>> the device but since USB_DEBUG was not enabled at that time so I was not
>> able to get more information out of it and being extremely intermittent in
>> nature, I am not able to reproduce it again. I am trying to figure out the
>> possible scenarios in which we might end up not attaching the driver to
>> the
>> device. I believe if we are not able to select a configuration then we
>> don't
>> attach the driver to the device.
>>
>> In usb_unconfigure func:
>>
>> udev->curr_config_no = USB_UNCONFIG_NO;
>> udev->curr_config_index = USB_UNCONFIG_INDEX
>>
>> In usb_probe_and_attach func:
>> if (udev->curr_config_index == USB_UNCONFIG_INDEX) {
>> /* do nothing - no configuration has been set */
>> goto done;
>> }
>>
>> From the console logs, it is clear that SET_ADDRESS went successfully,
>>> have
>>>
>> noticed that we have assigned a ugen name to the device and also request
>> to
>> get the String descriptors(Product, Manufacturer etc) went successfully so
>> that make me believe that there might be an error in performing
>> SET_CONFIGURATION request. Do you have any other suggestions?
>>
>
> You can use "usbdump" to figure out exactly what went wrong with regard to
> USB requests. That might get you a clearer picture of what's going on.
>
> --HPS
>
>
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