Backport UART fixes

[floitsch]

Backports of

• espressif@c062cd9
• espressif@d308465
• espressif@335273c

[github-actions]

	Warnings
⚠️	The **target branch** for this Pull Request **must be the default branch** of the project (`master`). If you would like to add this feature to a different branch, please state this in the PR description and we will consider it.

	Messages
📖	You might consider squashing your 3 commits (simplifying branch history).

👋 Hello floitsch, we appreciate your contribution to this project!

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[kasperl]

Looks good.