Re: [libusb] libusb-compat: failed to get config descriptor

[Anton S. <de...@an...>]

also it fails to set default (0) configuration with the same error message:
avrdude: usbdev_open(): error setting configuration 1: Device or resource
busy

the code:
if (dev->config == NULL)
          {
            fprintf(stderr,
            "%s: usbdev_open(): USB device has no configuration\n",
            progname);
            goto trynext;
          }


            fprintf(stderr, "settings configuration ...\n");
            if (usb_set_configuration(udev,
dev->config[0].bConfigurationValue))
          {
            fprintf(stderr,
            "%s: usbdev_open(): error setting configuration %d: %s\n",
            progname, dev->config[0].bConfigurationValue,
            usb_strerror());
            goto trynext;
          }


2013/7/31 Anton Smirnov <de...@an...>

> finally i was able to fix it by removing close(). interface count is now
> positive as i printed interface count before they were copied.
> now i'm having "device busy" error:
>
> avrdude: usbdev_open(): error claiming interface 1: Device or resource busy
>
> i'm trying to claim the right interface (found it using endpoints count =
> 2 for my board) of the right device (found it using pid/vid).
> interface was not claimed in android app but the device was just opened to
> get file descriptor.
>
> what can effect it? should i close the device before claiming interface?
>
>
> 2013/7/30 Anton Smirnov <de...@an...>
>
>> oh, i gave it a try and you were right, Toby!
>> It is invoked twice and the second attempt fails because it was closed in
>> the first attempt.
>>
>> So it seems to be liusb bug and it never worked for linux?
>>
>> Now i'm getting another error:
>>
>> 07-30 17:42:29.413: WARN/System.err(4536): [ 07-30 17:42:29.413  4536:
>> 8038 W/System.err ]
>>         Interfaces: 0
>> 07-30 17:42:29.413: WARN/System.err(4536): opened device
>> 07-30 17:42:29.413: WARN/System.err(4536): settings configuration ...
>> 07-30 17:42:29.413: WARN/System.err(4536): libusb-compat debug:
>> usb_set_configuration: configuration 1
>> 07-30 17:42:29.413: WARN/System.err(4536): libusb: 0.036655 debug
>> [libusb_set_configuration] configuration 1
>> 07-30 17:42:29.413: WARN/System.err(4536): avrdude: usbdev_open(): error
>> setting configuration 1: Device or resource busy
>>
>> It seems that getting configuration failed without error, as interface
>> count should be > 0 definitely
>>
>>
>>
>>
>>
>> 2013/7/30 Anton Smirnov <de...@an...>
>>
>>> Well, i just renamed op_get_config_descriptor to
>>> op_get_config_descriptor2 and introduced int fd parameter.
>>> Original source code contains closing:
>>> http://www.libusb.org/browser/libusb/libusb/os/linux_usbfs.csee op_get_config_descriptor()
>>>
>>> so i am not sure it's the problem.
>>> also closing is done after problem line:
>>> off = lseek(fd, DEVICE_DESC_LENGTH, SEEK_SET);
>>>
>>>
>>> 2013/7/30 Toby Gray <tob...@re...>
>>>
>>>>  On 30/07/13 12:18, Anton Smirnov wrote:
>>>>
>>>>  Thank you for helping, Toby.
>>>>
>>>>  > You are closing _fd before returning
>>>> Is it hypothesis or you've found where it's closing before returning?
>>>>
>>>>
>>>> The code you pasted closes it!
>>>>
>>>>
>>>>  I'm asking since the code is from libusb=0.1 and libusb-1.0 sources
>>>> and i did not introduce closing as far as i remember.
>>>>
>>>>
>>>> You did, you introduced op_get_config_descriptor2 which is closing the
>>>> file descriptor.
>>>>
>>>> Regards,
>>>>
>>>> Toby
>>>>
>>>>
>>>
>>
>