Re: [PATCH 5/5] usb: typec: fusb302: Enable SOP' communication

[sashiko-bot@kernel.org]

> Let TCPM discover e-marked cables through the FUSB302 and learn their
> current and speed ratings.
> 
> Receive SOP' only while sourcing VCONN with PD reception on. Only the
> VCONN Source talks to the cable plug, and acking the traffic between the
> partner and the plug would collide with their own GoodCRC.
> 
> Switch SOP' reception off before VCONN or PD reception goes off and on
> only once both are on. If that fails, log it instead of failing the
> switch TCPM asked for: SOP' reception left off only costs cable
> discovery, and left on with VCONN off makes the port ack the partner's
> traffic with the cable plug until PD reception goes off, which beats
> keeping VCONN or PD reception in a state TCPM did not request.
> 
> Tested on a FUSB302B as source with an e-marked 5A EPR cable. The
> datasheet documents the auto-GoodCRC header bits for SOP only, but the
> cable plug took the chip's acks to its SOP' replies without retrying.
> 
> Signed-off-by: Alexey Charkov <alchark@flipper.net>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261103-husb311-cable-comm-v1-0-6217dabc1a85@flipper.net?part=5