5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ilpo Järvinen ilpo.jarvinen@linux.intel.com
[ Upstream commit 84f2faa7852e1f55d89bb0c99b3a672b87b11f87 ]
Serial core handles serial_rs485 sanitization.
When em485 init fails, there are two possible paths of entry:
1) uart_rs485_config (init path) that fully clears port->rs485 on error.
2) ioctl path with a pre-existing, valid port->rs485 unto which the kernel falls back on error and port->rs485 should therefore be kept untouched. The temporary rs485 struct is not returned to userspace in case of error so its flag don't matter.
...Thus SER_RS485_ENABLED clearing on error can/should be dropped.
Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Link: https://lore.kernel.org/r/20220606100433.13793-37-ilpo.jarvinen@linux.intel.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/8250/8250_port.c | 18 ++---------------- 1 file changed, 2 insertions(+), 16 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 45a8f76f562e7..4fce318bc83ca 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -670,13 +670,6 @@ int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485) rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; }
- /* clamp the delays to [0, 100ms] */ - rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U); - rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U); - - memset(rs485->padding, 0, sizeof(rs485->padding)); - port->rs485 = *rs485; - gpiod_set_value(port->rs485_term_gpio, rs485->flags & SER_RS485_TERMINATE_BUS);
@@ -684,15 +677,8 @@ int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485) * Both serial8250_em485_init() and serial8250_em485_destroy() * are idempotent. */ - if (rs485->flags & SER_RS485_ENABLED) { - int ret = serial8250_em485_init(up); - - if (ret) { - rs485->flags &= ~SER_RS485_ENABLED; - port->rs485.flags &= ~SER_RS485_ENABLED; - } - return ret; - } + if (rs485->flags & SER_RS485_ENABLED) + return serial8250_em485_init(up);
serial8250_em485_destroy(up); return 0;