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From: Xu Yang <xu.yang_2@nxp.com>
To: badhri@google.com, heikki.krogerus@linux.intel.com,
	gregkh@linuxfoundation.org, arnaud.ferraris@collabora.com,
	dsimic@manjaro.org
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	imx@lists.linux.dev, jun.li@nxp.com
Subject: [PATCH v2 0/2] improve usb_role_switch_is_parent()
Date: Mon,  9 Mar 2026 15:43:11 +0800	[thread overview]
Message-ID: <20260309074313.2809867-1-xu.yang_2@nxp.com> (raw)

This patchset will revert a recent fix patch which will introduce another
regression, and fix the true underlying issue.

Arnaud pushed a fix patch commit 1366cd228b0c ("tcpm: allow looking for
role_sw device in the main node") because commit 2d8713f807a4
("tcpm: switch check for role_sw device with fw_node") swap the order of
usb_role_switch_get() and fwnode_usb_role_switch_get() and this cause the
fwnode_usb_role_switch_get() return "-EPROBE_DEFER" all the time in his
usecase.

The said dts use below property to get role switch device: 

  fusb0: typec-portc@22 {
  	  compatible = "fcs,fusb302";
  	  usb-role-switch = <&typec_extcon_bridge>;
  	  ...
   
  	  connector {
  	  }
  }

So the fix patch works because usb_role_switch_get() will correctly find
the role switch device in case fwnode_usb_role_switch_get() is failed.
However, usb_role_switch_get() shouldn't be called at all in this case
because tcpc->fwnode is already correctly set to @connector. And worse
more, this bring another issue that is once fwnode_usb_role_switch_get()
return "-EPROBE_DEFER" this info may be lost if usb_role_switch_get()
then return NULL.

After further research into this issue, finally I found
usb_role_switch_is_parent() not work properly when it parse non-boolean
"usb-role-switch" property which is for back compatibility purpose. To fix
the issue, patch#2 is added.

Xu Yang (2):
  Revert "tcpm: allow looking for role_sw device in the main node"
  usb: roles: get usb role switch from parent only for usb-b-connector

 drivers/usb/roles/class.c     | 7 ++++++-
 drivers/usb/typec/tcpm/tcpm.c | 2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)

-- 
2.34.1


             reply	other threads:[~2026-03-09  7:41 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-09  7:43 Xu Yang [this message]
2026-03-09  7:43 ` [PATCH v2 1/2] Revert "tcpm: allow looking for role_sw device in the main node" Xu Yang
2026-03-09  9:12   ` Arnaud Ferraris
2026-03-09  7:43 ` [PATCH v2 2/2] usb: roles: get usb role switch from parent only for usb-b-connector Xu Yang
2026-03-09  9:12   ` Arnaud Ferraris
2026-03-09 19:48   ` Frank Li
2026-03-10  2:47     ` Xu Yang
2026-03-09 11:32 ` [PATCH v2 0/2] improve usb_role_switch_is_parent() Heikki Krogerus

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