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

From: Tuomas Tynkkynen
Date: Thu May 05 2016 - 12:05:17 EST

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

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:

D'oh! Yes, that patch looks correct.

- Tuomas