[Spice-devel] [usbredir PATCH 5/6] usbredirhost: claim/release: ignore NOT_SUPPORTED on attach|detach kernel driver

[Hans de Goede]

Hi Xiaofan,

I did not know you where following this list too :)

On 05/04/2012 09:04 AM, Xiaofan Chen wrote:
> On Thu, May 3, 2012 at 11:04 PM, Uri Lublin<uril at redhat.com>  wrote:
>> On Windows libusb_(attach|detach)_kernel_driver are not supported.
>> A libusb driver is already installed (device was successfully opened).
>> In that case just continue as if operation was successful.
>> ---
>>   usbredirhost/usbredirhost.c |    4 +++-
>>   1 files changed, 3 insertions(+), 1 deletions(-)
>>
>> diff --git a/usbredirhost/usbredirhost.c b/usbredirhost/usbredirhost.c
>> index 305dd35..3d77ac8 100644
>> --- a/usbredirhost/usbredirhost.c
>> +++ b/usbredirhost/usbredirhost.c
>> @@ -486,7 +486,8 @@ static int usbredirhost_claim(struct usbredirhost *host, int initial_claim)
>>          n = host->config->interface[i].altsetting[0].bInterfaceNumber;
>>
>>          r = libusb_detach_kernel_driver(host->handle, n);
>> -        if (r<  0&&  r != LIBUSB_ERROR_NOT_FOUND) {
>> +        if (r<  0&&  r != LIBUSB_ERROR_NOT_FOUND
>> +&&  r != LIBUSB_ERROR_NOT_SUPPORTED) {
>>              ERROR("could not detach driver from interface %d (configuration %d): %d",
>>                    n, host->config->bConfigurationValue, r);
>>              return libusb_status_or_error_to_redir_status(host, r);
>> @@ -544,6 +545,7 @@ static void usbredirhost_release(struct usbredirhost *host, int attach_drivers)
>>          r = libusb_attach_kernel_driver(host->handle, n);
>>          if (r<  0&&  r != LIBUSB_ERROR_NOT_FOUND /* No driver */
>>                    &&  r != LIBUSB_ERROR_NO_DEVICE /* Device unplugged */
>> +&&  r != LIBUSB_ERROR_NOT_SUPPORTED /* Not supported */
>>                    &&  r != LIBUSB_ERROR_BUSY /* driver rebound already */) {
>>              ERROR("could not re-attach driver to interface %d (configuration %d): %d",
>>                    n, host->config->bConfigurationValue, r);
>> --
>> 1.7.7.6
>
> To me the above is not the right fix, the right fix is to limit the call
> libusb_detach_kernel_driver() to Linux only. Do not use this
> call for other systems since all the other OS does not support this
> call -- be it Mac OS X, Windows, or BSDs.

I agree that an #ifdef __linux__ would be a good fix too. Note that the NOT_SUPPORTED
check will work as well, but you're right that we might just as well #ifdef out the
code.

Regards,

Hans