Hi Lyf, If the device sent a full packet (max packet size bytes for the endpoint), but the read API call was for more data, the transfer is not considered complete. The callback will only be run when either the device sends a short packet (meaning less than max packet size bytes), or it has sent enough bytes to fully satisfy the read.
To debug further, you can try adjusting the read length passed into the API, or make sure the device sends a short packet when the interrupt payload has transferred. Thanks, Dan > On Oct 30, 2015, at 9:32 AM, lyf4 Science <[email protected]> wrote: > > Hi Experts, > > I had developed a sample USB driver in MAC OS X 10.10 to read from Interrupt > IN endpoint of a device. I registered callback with the Interrupt IN read() > api. > > On analysis with hardware USB analyzer the Interrupt IN data is read by host > from device and ACK is sent but the host driver dosen't invokes the callback. > > How to debug the issue ? > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Usb mailing list ([email protected]) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/usb/wilson_daniel%40apple.com > > This email sent to [email protected] _______________________________________________ Do not post admin requests to the list. They will be ignored. Usb mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/usb/archive%40mail-archive.com This email sent to [email protected]
