[U-Boot] [PATCH] ehci: speed up initialization

[Wolfgang Grandegger <wg@grandegger.com>]

On 12/10/2011 05:29 PM, Remy Bohmer wrote:
> Hi,
> 
> 2011/12/5 Vincent Palatin <vpalatin@chromium.org>:
>> According to EHCI specification v1.0, the controller should stabilize
>> the power on a port at most 20 ms after the port power bit transition.
>> So, we put this setting in the virtual descriptor corresponding field,
>> (bPwrOn2PwrGood = 10 => 10 x 2ms = 20ms), this saves about 500ms at each
>> controller initialization/enumeration.
>>
>> Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
>> ---
>>  drivers/usb/host/ehci-hcd.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> Applied to u-boot-usb.

I just realized that this patch breaks "usb start" on my mx53loco board:

  MX53LOCO U-Boot > usb start
  (Re)start USB...
  USB:   Register 10011 NbrPorts 1
  USB EHCI 1.00
  scanning bus for devices... 1 USB Device(s) found
         scanning bus for storage devices... 0 Storage Device(s) found
         scanning bus for ethernet devices... 0 Ethernet Device(s) found

  MX53LOCO U-Boot > usb start
  (Re)start USB...
  USB:   Register 10011 NbrPorts 1
  USB EHCI 1.00
  scanning bus for devices... 2 USB Device(s) found
         scanning bus for storage devices... 0 Storage Device(s) found
         scanning bus for ethernet devices... 1 Ethernet Device(s) found

The device is not found at the first attempt. Obviously, a value of 10
for bPwrOn2PwrGood seems too short but 20 works fine. Would that be a
resonable compromise? If yes, I could send a patch.

Wolfgang.

Wolfgang.