[U-Boot] [PATCH 2/7] usb: hub: Conditionally power on usb's root-hub ports

[Vivek Gautam]

Hi Marek,

Adding CC: Amarendra

On Thu, Mar 28, 2013 at 7:58 PM, Marek Vasut <marex at denx.de> wrote:
> Dear Vivek Gautam,
>
>> Power on root hubs' ports only when they are not yet powered on.
>> Its seen with USB 3.0 ports that they are powered on after
>> a H/W reset, as also reflected in XHCI spec (sec 4.3):
>> "After a Chip Hardware Reset, HCRST, or commanded to the
>> PLS = RxDetect state, all Root Hub ports shall be in Disconnected
>> state, i.e. the port is powered on (PP = 1)"
>>
>> Signed-off-by: Amar <amarendra.xt at samsung.com>
>> Signed-off-by: Vivek Gautam <gautam.vivek at samsung.com>
>
> Just wondering if we shouldn't power-cycle all the ports instead -- aka. turn
> them off and then turn all of them on again.

Hmm, seems like a fine idea.
Will it be fine to power-cycle even EHCI ports too ?
Or we just check if ports are already powered-up (as in XHCI) we
power-cycle them.



-- 
Thanks & Regards
Vivek