Re: kqueue for usb_dev

On 02/27/14 07:02, John-Mark Gurney wrote:
> 2) Why do you try to start read/write transfers in the _filter?  You
> should just check to see if data is available and not do work..  This
> is also important since kqueue calls the filter just before delivering
> the knote to userland to verify that there is still data, and it will
> call your _event function for each knote on the fd...  The work should
> be started through other mechanisms, like read/write syscall or
> interrupt or timeout/callout...  If it's required to get results from
> USB_IF_POLL, then it's fine..

Hi,

In the case where you start polling and don't do any reads or writes, 
the poller needs to get the data traffic going.

--HPS