Re: [PATCH v1] usb: typec: tcpm: Wait for vbus discharge to VSAFE0V before toggling

From: Greg Kroah-Hartman
Date: Thu Feb 18 2021 - 07:37:13 EST


On Thu, Feb 18, 2021 at 02:38:45AM -0800, Badhri Jagan Sridharan wrote:
> Hi Greg,
>
> This patch is a bug fix for the following patch which was introduced in 5.11.
>
> commit f321a02caebdd0c56e167610cda2fa148cd96e8b
> Author: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
> Date: Wed Oct 28 23:31:35 2020 -0700
>
> usb: typec: tcpm: Implement enabling Auto Discharge disconnect support
>
> TCPCI spec allows TCPC hardware to autonomously discharge the vbus
> capacitance upon disconnect. The expectation is that the TCPM enables
> AutoDischargeDisconnect while entering SNK/SRC_ATTACHED states. Hardware
> then automously discharges vbus when the vbus falls below a certain
> threshold i.e. VBUS_SINK_DISCONNECT_THRESHOLD.
>
> Apart from enabling the vbus discharge circuit, AutoDischargeDisconnect
> is also used a flag to move TCPCI based TCPC implementations into
> Attached.Snk/Attached.Src state as mentioned in
> Figure 4-15. TCPC State Diagram before a Connection of the
> USB Type-C Port Controller Interface Specification.
> In such TCPC implementations, setting AutoDischargeDisconnect would
> prevent TCPC into entering "Connection_Invalid" state as well.
>
> Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> Link: https://lore.kernel.org/r/20201029063138.1429760-8-badhri@xxxxxxxxxx
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Great, then can you resend the patch and add a proper Fixes: tag, along
with a cc: stable as well?

thanks,

greg k-h