Quoting Peter Chen (2017-01-21 18:10:59)

On Fri, Jan 20, 2017 at 10:50:54AM -0800, Stephen Boyd wrote:

quoted

When the qcom chipidea controller is used with an extcon, we need
to signal device mode or host mode to the phy so it can configure
itself for the correct mode. This should be done after the phy is
powered up, so that the register writes work correctly. Add in
the appropriate phy_set_mode() call here.

To signal the correct state to the qcom glue driver we need to
change the ci->role before we do the role switch. Make sure to
undo the change if the role switch fails, but otherwise update
the state before calling the role start function so that the glue
driver knows what state to configure for.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <redacted>
---

Made this msm specific because of how msm handles phy powerup.

 drivers/usb/chipidea/ci.h          | 7 +++++--
 drivers/usb/chipidea/ci_hdrc_msm.c | 4 ++++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h
index 59e22389c10b..18348b0529af 100644
--- a/drivers/usb/chipidea/ci.h
+++ b/drivers/usb/chipidea/ci.h

@@ -268,6 +268,7 @@ static inline struct ci_role_driver *ci_role(struct ci_hdrc *ci)
 static inline int ci_role_start(struct ci_hdrc *ci, enum ci_role role)
 {
      int ret;
+     enum ci_role prev_role;
 
      if (role >= CI_ROLE_END)
              return -EINVAL;

@@ -275,9 +276,11 @@ static inline int ci_role_start(struct ci_hdrc *ci, enum ci_role role)
      if (!ci->roles[role])
              return -ENXIO;
 
+     prev_role = ci->role;
+     ci->role = role;
      ret = ci->roles[role]->start(ci);
-     if (!ret)
-             ci->role = role;
+     if (ret)
+             ci->role = prev_role;
      return ret;

Sorry, this changes ci->role's life cycle. You may try to get coming
role at your glue layer code (eg, through usbmode), or add your
changes at ci_role_start directly if the sequence can make your requirement.

Ok I'll add the phy_set_mode() hooks into ci_platform_configure() and
see how that goes. Both udc.c and host.c call into that function at the
right time.