ChibiOS Free Embedded RTOS

This patch that moves the 'read DR' into the existing error handling.
By this, the DR is only read in case of an error, which include the ORE. In the case of no error, the DR is not read and no bytes get lost.

Ok. Will do.

Hi,

That function is meant to handle errors, it is done in case there is an ORE to be handled, from the STM32 RM:

"The ORE bit is reset by a read to the USART_SR register followed by a USART_DR register read operation."

Giovanni

Hi Giovanni

That's correct. However, by unconditionally reading ...

In uart_lld_serve_interrupt() of the STM32/USARTv1 implementation, the following line reads the data register, clearing it by that:

(void)u->DR; /* SR reset step 2.*/

This causes a problem in the following context:
- DMA is IDLE
- An send operation is started
- The UART receives a single byte and ...

Fixed patch to match description. Sorry.

Hi there

I'm working on a port of our BTstack Bluetooth Host stack for ChibiOS. BTstack's transport layer requests data from the UART in blocks and uses CTS/RTS to avoid loosing bytes. The trunk ChibiOS/HAL implementation in uart_enter_rx_idle_loop() unconditionally restarts the UART DMA leading to ...