]> www.infradead.org Git - users/jedix/linux-maple.git/commit
usb:typec:tcpm:support double Rp to Vbus cable as sink
authorMichael Wu <michael@allwinnertech.com>
Wed, 20 Sep 2023 06:30:30 +0000 (14:30 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 2 Oct 2023 14:32:44 +0000 (16:32 +0200)
commitdbc1defec1aa7d8d80da3ea9e3ddafbcfca8f822
tree2a2bf37f80cc5aa0e3e0f15766f28ed5d239f6e7
parent5c954e030f55b40b0b538c66d1a49a91b727f4dc
usb:typec:tcpm:support double Rp to Vbus cable as sink

The USB Type-C Cable and Connector Specification defines the wire
connections for the USB Type-C to USB 2.0 Standard-A cable assembly
(Release 2.2, Chapter 3.5.2).
The Notes says that Pin A5 (CC) of the USB Type-C plug shall be connected
to Vbus through a resister Rp.
However, there is a large amount of such double Rp connected to Vbus
non-standard cables which produced by UGREEN circulating on the market, and
it can affects the normal operations of the state machine easily,
especially to CC1 and CC2 be pulled up at the same time.
In fact, we can regard those cables as sink to avoid abnormal state.

Message as follow:
[   58.900212] VBUS on
[   59.265433] CC1: 0 -> 3, CC2: 0 -> 3 [state TOGGLING, polarity 0, connected]
[   62.623308] CC1: 3 -> 0, CC2: 3 -> 0 [state TOGGLING, polarity 0, disconnected]
[   62.625006] VBUS off
[   62.625012] VBUS VSAFE0V

Signed-off-by: Michael Wu <michael@allwinnertech.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20230920063030.66312-1-michael@allwinnertech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/typec/tcpm/tcpm.c