Fix STM32H5 UCPD reception #3811
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On STM32H5 (with GPDMA), I saw some USB PD reception appearing to be empty, when packets were arriving quickly back-to-back.
When calling
receiveon the UCPD driver, you would usually provide a buffer big enough to cover the biggest standard packet type (e.g. 30 byte). The DMA will store data in the buffer, until its number of transfers are reached, even if this means handling multiple UCPD requests.It turns out that the DMA got two requests from the UCPD peripheral during one receive operation and advanced the memory pointer by itself. The UCPD driver did not stop the DMA after receiving a full message. Multiple messages ended up in the same buffer, concatenated.
This PR stops the DMA after receiving a packet, or a hard reset.
Tested with https://github.com/elagil/usbpd/tree/main/examples/embassy-nucleo-h563zi