Am Mittwoch, 4. November 2015, 14:53:02 schrieb Douglas Anderson: > The dwc2 interrupt handler is quite slow. On rk3288 with a few things > plugged into the ports and with cpufreq locked at 696MHz (to simulate > real world idle system), I can easily observe dwc2_handle_hcd_intr() > taking > 120 us, sometimes > 150 us. Note that SOF interrupts come > every 125 us with high speed USB, so taking > 120 us in the interrupt > handler is a big deal. > > The patches here will speed up the interrupt controller significantly. > After this series, I have a hard time seeing the interrupt controller > taking > 20 us and I don't ever see it taking > 30 us ever in my tests > unless I bring the cpufreq back down. With the cpufreq at 126 MHz I can > still see the interrupt handler take > 50 us, so I'm sure we could > improve this further. ...but hey, it's a start. > > In addition to the speedup, this series also has the advantage of > simplifying dwc2 and making it more like everyone else (introducing the > possibility of future simplifications). Picking this series up will > help your diffstat and likely win you friends. ;) I gave this a simple spin on my veyron-pinky with both a device attached directly to the port as well as with an usb-hub in between. Everything was still working smoothly, so Tested-by: Heiko Stuebner <heiko@xxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
