Commit 7388970c authored Nov 28, 2023 by Dawid Niedzwiecki Committed by Carles Cufi Nov 30, 2023

serial: stm32: do not clear TC flag in async mode



The Transfer Complete flag (TC) is used to check if a transfer is
complete. This mechanism is used before suspending the UART module to
make sure that all data are sent before the suspend procedure.

The UART ISR clears this flag after completion of a async transfer which
causes a hang during UART device suspend setup.

There is just no need to clear this flag in ISR, it is cleared every
time we start a new async transfer.

Signed-off-by: Dawid Niedzwiecki <dawidn@google.com>

parent e6f77f9b

drivers/serial/uart_stm32.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -1257,7 +1257,6 @@ static void uart_stm32_isr(const struct device *dev)
		LL_USART_IsActiveFlag_TC(config->usart)) {

		LL_USART_DisableIT_TC(config->usart);
		LL_USART_ClearFlag_TC(config->usart);
		/* Generate TX_DONE event when transmission is done */
		async_evt_tx_done(data);

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