Re: [PATCH v3 1/2] usb: host: ehci-tegra: Grab the correct UTMI pads reset

[Tuomas Tynkkynen]

On 05/04/2016 06:26 PM, Thierry Reding wrote:
> On Wed, May 04, 2016 at 07:57:10AM -0700, Greg Kroah-Hartman wrote:
> > On Wed, May 04, 2016 at 04:39:59PM +0200, Thierry Reding wrote:
> > > From: Thierry Reding <treding@xxxxxxxxxx>
> > >
> > > There are three EHCI controllers on Tegra SoCs, each with its own reset
> > > line. However, the first controller contains a set of UTMI configuration
> > > registers that are shared with its siblings. These registers will only
> > > be reset as part of the first controller's reset. For proper operation
> > > it must be ensured that the UTMI configuration registers are reset
> > > before any of the EHCI controllers are enabled, irrespective of the
> > > probe order.
> > >
> > > Commit a47cc24cd1e5 ("USB: EHCI: tegra: Fix probe order issue leading to
> > > broken USB") introduced code that ensures the first controller is always
> > > reset before setting up any of the controllers, and is never again reset
> > > afterwards.
> > >
> > > This code, however, grabs the wrong reset. Each EHCI controller has two
> > > reset controls attached: 1) the USB controller reset and 2) the UTMI
> > > pads reset (really the first controller's reset). In order to reset the
> > > UTMI pads registers the code must grab the second reset, but instead it
> > > grabbing the first.
> > >
> > > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
...snip ...
> While at it, adding Tuomas who wrote the original probe order fix.
> Tuomas, does this patch look correct to you? Here's the patch in full if
> you don't have it in your inbox:
>
> 	http://patchwork.ozlabs.org/patch/618488/

D'oh! Yes, that patch looks correct.

- Tuomas