Hi Stefan, On Tue, Mar 15, 2016 at 8:59 PM, Stefan Roese <s...@denx.de> wrote: > > My current x86 platform (Bay Trail, not in mainline yet) has a quite > complex USB infrastructure with many USB hubs. Here the USB scan takes > an incredible huge amount of time: > > starting USB... > USB0: USB EHCI 1.00 > scanning bus 0 for devices... 9 USB Device(s) found > > time: 28.415 seconds > > This is of course not acceptable on platforms, where USB needs to get > scanned at every bootup. As this increases the bootup time of this > device by nearly 30 seconds! > > This patch series greatly reduces the USB scanning time. This is done > by multiple means: > > - Remove or reduce delays and timeouts > - Remove a 2nd reset of the USB hubs > - Change USB port timeout handling and introduce quasi parallel USB > port scanning > > As a result, the USB scanning time is greatly reduced: > > starting USB... > USB0: USB EHCI 1.00 > scanning bus 0 for devices... 9 USB Device(s) found > > time: 1.822 seconds > > As you can see, the time is reduced from 28.4 to 1.8 seconds! > > Please find more details to the changes in the patch description. > > Testing and comments welcome! > > Thanks, > Stefan >
This is a great improvement. Thanks! Some numbers FYI. I've tested the v5 patch on Intel Crown Bay. The 'usb start' command takes about 3 seconds to finish, compared to previously 9 seconds. Regards, Bin _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
