From: Pali Rohár pali@kernel.org
[ Upstream commit ecd6b010d81f97b06b2f64d2d4f50ebf5acddaa9 ]
Testing mvuart->clk for non-error is not enough as mvuart->clk may contain valid clk pointer but when clk_prepare_enable(mvuart->clk) failed then port->uartclk is zero.
When mvuart->clk is not available then port->uartclk is zero too.
Parent clock rate port->uartclk is needed to calculate UART clock divisor and without it is not possible to change baudrate.
So fix test condition when it is possible to change baudrate.
Signed-off-by: Pali Rohár pali@kernel.org Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate") Link: https://lore.kernel.org/r/20210624224909.6350-3-pali@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/mvebu-uart.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c index 908a4ac6b5a7..9638ae6aae79 100644 --- a/drivers/tty/serial/mvebu-uart.c +++ b/drivers/tty/serial/mvebu-uart.c @@ -445,12 +445,11 @@ static void mvebu_uart_shutdown(struct uart_port *port)
static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud) { - struct mvebu_uart *mvuart = to_mvuart(port); unsigned int d_divisor, m_divisor; u32 brdv, osamp;
- if (IS_ERR(mvuart->clk)) - return -PTR_ERR(mvuart->clk); + if (!port->uartclk) + return -EOPNOTSUPP;
/* * The baudrate is derived from the UART clock thanks to two divisors: