On 12/10/2011 05:29 PM, Remy Bohmer wrote:
> Hi,
>
> 2011/12/5 Vincent Palatin <vpala...@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 <vpala...@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.
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