dwc_otg: implement tasklet for returning URBs to usbcore hcd layer
The dwc_otg driver interrupt handler for transfer completion will spend a very long time with interrupts disabled when a URB is completed - this is because usb_hcd_giveback_urb is called from within the handler which for a USB device driver with complicated processing (e.g. webcam) will take an exorbitant amount of time to complete. This results in missed completion interrupts for other USB packets which lead to them being dropped due to microframe overruns. This patch splits returning the URB to the usb hcd layer into a high-priority tasklet. This will have most benefit for isochronous IN transfers but will also have incidental benefit where multiple periodic devices are active at once.
parent
e959a8e5
Please register or sign in to comment