[U-Boot] [PATCH 13/16] usb: ohci: Remove unnecessary delays from hc_start and power power-on paths

[Hans de Goede]

Hi,

On 06-05-15 01:01, Marek Vasut wrote:
> On Tuesday, May 05, 2015 at 11:56:16 PM, Hans de Goede wrote:
>> The common usb_hub code already waits a full second after powering up
>> ports, so there is no need for additional delays inside the hcd code.
>>
>> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
>
> This makes a driver depend on the behavior of the subsystem, which might
> change though, right ?  Won't this bite us in the future ?

Well since the usb spec says that we must wait a minimum amount of time
after port power on (exact time is in the hub descriptor) the subsys code
better not change otherwise we would be violating the spec in the future,
also note that we must not only do the wait for root ports but also
for external hub ports, so we can really never drop the wait from the
subsys code, and having a separate wait for just the root hub in the hcd
code will only lead to doing the waiting twice.

I'll change the commit message to make this clear.

Regards,

Hans