On Wed, Jul 03, 2024 at 09:37:13AM +0200, Stefan Eichenberger wrote:
> 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?
Should now be fixed up, thanks.
greg k-h
