Re: [Libusb-devel] trouble clearing a timeout

[Danny R. <dk...@ra...>]

Johannes Erdfelt wrote:
> On Tue, Jun 22, 2004, Danny Rathjens <dk...@ra...> wrote:
> 
>>I wrote an app that uses usb_interrupt_read to read card data
>>from a card swipe device.  I wanted to clear any existing data
>>before accepting a new swipe so I made a loop that called
>>usb_interrupt_read with a timeout of 10 milliseconds until
>>it times out.  Then I want to get the current card swipe,
>>which means I call usb_interrupt_read again with a timeout of
>>30 seconds(and then a bunch more to get rest of track data).
>>
>>My problem is that the call to usb_interrupt_read with a
>>timout of 30 seconds is returning immediately with a timeout.
>>It seems as if the timeout status has been cached somehow.
>>Calling usb_clear_halt did not help.
>>
>>My somewhat kludgy solution was to release the interface,
>>close the usb_dev_handle, re-open the device, re-claim
>>the interface, re-set altinterface, and then make the
>>usb_interrupt_read call with a 30 second timeout.
>>
>>Any idea how to do this in a less kludgy manner?  Oh yeah,
>>I also tried sleeping for a bit in between clearing the
>>buffered swipe and attempting to read the new one.
> 
> 
> What version of libusb are you using? There was a bug at one time that
> would result in that behaviour.
> 
> Have you tried the version out of CVS?
> 
Thanks for the reply.  I am using libusb-0.1.8 with linux-2.4.26.
I shall check out the CVS version.
-- 
     _.,-*~`^'~*-,._ Danny Rathjens _.,-*~`^'~*-,._
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