Hi,
On 11-03-16 18:53, Stephen Warren wrote:
On 03/11/2016 07:55 AM, Stefan Roese 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: 4.606 seconds
As you can see, the time is reduced from 28.4 to 4.6 seconds!
Please find more details to the changes in the patch description.
Testing and comments welcome!
The series, Tested-by: Stephen Warren swarren@nvidia.com (same set of tests as last time)
And the entire series looks good to me (note not tested only reviewed) :
Acked-by: Hans de Goede hdegoede@redhat.com
Thank you for working on this.
Regards,
Hans