Hi Greg,
On Tue, Jul 02, 2024 at 07:04:52PM +0200, Greg Kroah-Hartman wrote:
> 6.1-stable review patch. If anyone has any objections, please let me know.
>
> ------------------
>
> From: Stefan Eichenberger <stefan.eichenberger@xxxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Signed-off-by: Stefan Eichenberger <stefan.eichenberger@xxxxxxxxxxx>
> Link: https://lore.kernel.org/r/20240621153829.183780-1-eichest@xxxxxxxxx
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
> 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
> @@ -1978,8 +1978,10 @@ 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;
> }
Unfortunately, I introduced a regression with this patch. The problem
was detected by our automated tests when running a loopback test with
SDMA enabled. Please do not apply this patch to any stable branch. I
could provide a fix for mainline on top of this change, or would you
prefer to revert it for now?
Sorry for the inconvenience,
Stefan
