On Saturday, September 20, 2014 at 05:01:05 PM, Hans de Goede wrote:
Hi Marek,
This time a patch-set for next :)
Currently one can choose between 2 poll methods for usb keyboards, both of which are suboptimal. One option is to use control messages to get reports, which some devices (e.g. my kvm) do not like. The other option is to use interrupt urbs, but usb_submit_int_msg waits for the interrupt packet to show up, meaning that each poll takes 40 ms, slowing anything else down tremendously.
This patch-sets adds a third method (only usable with ehci for now), which makes use of the int_queue concept in the ehci code. This allows us to submit an interrupt message, and then poll for the actual completion of this message giving us much lower latency then even the control message method (effectively this gives us 0 latency), while using standard interrupt messages which seems to keep keyboards much happier.
I'd be happy to just pick V2 as it would be. The patches look really nice.
Best regards, Marek Vasut