From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marek Vasut <marex@denx.de>
Date: Tue, 2 Apr 2013 12:09:08 +0200
Subject: [U-Boot] [PATCH 2/7] usb: hub: Conditionally power on usb's
	root-hub ports
In-Reply-To: <CAFp+6iHBgh4OQCD9-mjh=_P_v_1syJKkhmfUfeVKDeNfm6=H3g@mail.gmail.com>
References: <1364376543-7526-1-git-send-email-gautam.vivek@samsung.com>
	<201303281528.03266.marex@denx.de>
	<CAFp+6iHBgh4OQCD9-mjh=_P_v_1syJKkhmfUfeVKDeNfm6=H3g@mail.gmail.com>
Message-ID: <201304021209.08480.marex@denx.de>
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Dear Vivek Gautam,

> Hi Marek,
> 
> Adding CC: Amarendra
> 
> On Thu, Mar 28, 2013 at 7:58 PM, Marek Vasut <marex@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@samsung.com>
> >> Signed-off-by: Vivek Gautam <gautam.vivek@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 ?

Best regards,
Marek Vasut