ba1f8e5474
stm32f7: serial: Fix ioctl TIOCSSINGLEWIRE The TRM notes that UE must be disabled in order to write HDSEL in USART_CR3. This was not being done, so calls to TIOCSSINGLEWIRE were silently failing. This change checks the state of UE in USART_CR1, clears the UE bit before writing HDSEL, then re-enables it if neccesary. Approved-by: GregoryN <gnutt@nuttx.org>