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

[Vivek Gautam]

Hi,


On Tue, Apr 2, 2013 at 3:39 PM, Marek Vasut <marex at denx.de> wrote:
> Dear 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.
>
> EHCI as well, all of them without differentiating the type. Why not , do you see
> a problem ?

Not of course, will amend this accordingly.


-- 
Thanks & Regards
Vivek