Commit 5c5f44e3 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Greg Kroah-Hartman
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serial: stm32: Clear prev values before setting RTS delays 



The code lacks clearing of previous DEAT/DEDT values. Thus, changing
values on the fly results in garbage delays tending towards the maximum
value as more and more bits are ORed together. (Leaving RS485 mode
would have cleared the old values though).

Fixes: 1bcda09d ("serial: stm32: add support for RS485 hardware control mode")
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220627150753.34510-1-ilpo.jarvinen@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ec5ad331

drivers/tty/serial/stm32-usart.c

+2 −0
Original line number Diff line number Diff line
@@ -72,6 +72,8 @@ static void stm32_usart_config_reg_rs485(u32 *cr1, u32 *cr3, u32 delay_ADE, 
	*cr3 |= USART_CR3_DEM;

	over8 = *cr1 & USART_CR1_OVER8;



	*cr1 &= ~(USART_CR1_DEDT_MASK | USART_CR1_DEAT_MASK);



	if (over8)

		rs485_deat_dedt = delay_ADE * baud * 8;

	else