6.9-stable review patch. If anyone has any objections, please let me know.
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From: Stefan Eichenberger stefan.eichenberger@toradex.com
commit a81dbd0463eca317eee44985a66aa6cc2ce5c101 upstream.
Set the receiver level to something > 0 before calling imx_uart_start_rx in rs485_config. This is necessary to avoid an interrupt storm that might prevent the system from booting. This was seen on an i.MX7 device when the rs485-rts-active-low property was active in the device tree.
Fixes: 6d215f83e5fc ("serial: imx: warn user when using unsupported configuration") Cc: stable stable@kernel.org Signed-off-by: Stefan Eichenberger stefan.eichenberger@toradex.com Link: https://lore.kernel.org/r/20240621153829.183780-1-eichest@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tty/serial/imx.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1960,8 +1960,10 @@ static int imx_uart_rs485_config(struct
/* Make sure Rx is enabled in case Tx is active with Rx disabled */ if (!(rs485conf->flags & SER_RS485_ENABLED) || - rs485conf->flags & SER_RS485_RX_DURING_TX) + rs485conf->flags & SER_RS485_RX_DURING_TX) { + imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT); imx_uart_start_rx(port); + }
return 0; }