Hey everyone!
In our app we use HAL_UARTEx_ReceiveToIdle_DMA() to capture serial data to a circular buffer (same as ST Sample 'UART_ReceptionToIdle_CircularDMA UART). It works really well until someone plugs or unplugs cables generating noise on the UART. In this case, we just poll HAL_UART_GetError(), reset the uart using HAL_UART_Init(), and finally call HAL_UARTEx_ReceiveToIdle_DMA() again to recover.
The errors returned could be noise, parity, or framing errors (we've seen all 3). The recovery works 95% of the time. But, 5% of the time, after resetting the uart with HAL_UART_Init(), we will enter HAL_UARTEx_ReceiveToIdle_DMA() and it will permanently block/never return.
We mitigated this condition by inserting a 50ms delay in between HAL_UART_Init() and HAL_UARTEx_ReceiveToIdle_DMA(). I don't feel super good about this and would rather be checking a flag but I have no idea what condition is causing HAL_UARTEx_ReceiveToIdle_DMA() to block. I cannot get the issue (which has a 5% chance of happening) to occur with a DEBUG build because of added debug bulk serving as a delay and possibly fixing the issue. This makes the exact problem hard to debug.
Anyone ever seen this case?
