On 04/02/2016 11:21 PM, Hans de Goede wrote:
Hi,
Hi!
On 04/02/2016 12:22 AM, Marek Vasut wrote:
On 03/15/2016 01:59 PM, Stefan Roese wrote:
This patch changes the USB port scanning procedure and timeout handling in the following ways:
a) The power-on delay in usb_hub_power_on() is now reduced to a value of max(100ms, "hub->desc.bPwrOn2PwrGood * 2"). The code does not wait using mdelay, instead usb_hub_power_on() will wait before querying the device in the scanning loop later. The total timeout for this hub, which is 1 second + "hub->desc.bPwrOn2PwrGood * 2" is calculated and will be used in the following per-port scanning loop as the timeout to detect active USB devices on this hub.
b) Don't delay the minimum delay (for power to stabilize) in usb_hub_power_on(). Instead skip querying these devices in the scannig loop until the delay time is reached.
c) The ports are now scanned in a quasi parallel way. The current code did wait for each (unconnected) port to reach its timeout and only then continue with the next port. This patch now changes this to scan all ports of all USB hubs quasi simultaneously. For this, all ports are added to a scanning list. This list is scanned until all ports are ready by either a) reaching the connection timeout (calculated earlier), or by b) detecting a USB device. This results in a faster USB scan time as the recursive scanning of USB hubs connected to the hub that's currently being scanned will start earlier.
One small functional change to the original code is, that ports with overcurrent detection will now get rescanned multiple times (PORT_OVERCURRENT_MAX_SCAN_COUNT).
Without this patch: starting USB... USB0: USB EHCI 1.00 scanning bus 0 for devices... 9 USB Device(s) found
time: 20.163 seconds
With this patch: starting USB... USB0: USB EHCI 1.00 scanning bus 0 for devices... 9 USB Device(s) found
time: 1.822 seconds
So ~18.3 seconds of USB scanning time reduction.
Signed-off-by: Stefan Roese sr@denx.de Acked-by: Hans de Goede hdegoede@redhat.com Tested-by: Stephen Warren swarren@nvidia.com
This breaks DWC2 on SoCkit, I can no longer detect any USB device. USB works without this patch though. Ideas?
Have you tried simply adding a large sleep before the initial uart, or doing an "usb reset" after the initial scan ?
Yeah, that doesn't help. But I also sent a few fixes for the DWC2 controller, so let's see. I also finally got Stefan a working board, so he can start poking around :)
The biggest change here is the change in timing ...
Also try defining debug printf in usb_hub.c and see what output you get ?
I'll be offloading this to Stefan :)
Regards,
Hans