Monthly summary for 2026-05: Focused on a critical reliability improvement in USB-C PD negotiation within the Zephyr TCPC driver by fixing non-SOP transmission handling. The fix ensures proper classification of PD messages and aligns the decision gate with the actual packet type used in retries, reducing misclassification caused by header overlaps and CC-line noise.

March 2026 monthly summary for zephyrproject-rtos/zephyr focused on stabilizing PD control message transmission in the USB-C TCPCI path. Fixed a bug where PD control messages with no data objects could be skipped due to a cnt=0 condition; the fix gates TX buffer writes on the message type to ensure control messages are transmitted correctly. Implemented in commit 31222decf07a0d23d1f1cea2bdca907abcccd306, with verification that control messages are reliably processed during PD negotiations. Result: more reliable PD messaging, fewer transmission gaps, and improved hardware interoperability.