On Wed, Sep 20, 2023 at 02:30:30PM +0800, Michael Wu wrote:
> 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@xxxxxxxxxxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> v1 -> v2: Simplify expression and add a comment to the code.
>
> drivers/usb/typec/tcpm/tcpm.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> Signed-off-by: Michael Wu <michael@xxxxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/tcpm/tcpm.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index d962f67c95ae6..6e843c511b856 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -517,9 +517,9 @@ static const char * const pd_rev[] = {
> ((cc) == TYPEC_CC_RP_DEF || (cc) == TYPEC_CC_RP_1_5 || \
> (cc) == TYPEC_CC_RP_3_0)
>
> +/* As long as cc is pulled up, we can consider it as sink. */
> #define tcpm_port_is_sink(port) \
> - ((tcpm_cc_is_sink((port)->cc1) && !tcpm_cc_is_sink((port)->cc2)) || \
> - (tcpm_cc_is_sink((port)->cc2) && !tcpm_cc_is_sink((port)->cc1)))
> + (tcpm_cc_is_sink((port)->cc1) || tcpm_cc_is_sink((port)->cc2))
>
> #define tcpm_cc_is_source(cc) ((cc) == TYPEC_CC_RD)
> #define tcpm_cc_is_audio(cc) ((cc) == TYPEC_CC_RA)
> --
> 2.29.0
--
heikki
