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

[Marek Vasut]

On Sunday, May 10, 2015 at 11:10:00 AM, Hans de Goede wrote:
> Hi,

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.

Thanks!

Best regards,
Marek Vasut