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authorPali Rohár <pali@kernel.org>2021-06-25 00:49:01 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-06-25 13:53:20 +0200
commitecd6b010d81f97b06b2f64d2d4f50ebf5acddaa9 (patch)
tree702ca207a0b0ee57d95b8f0a9ca663c9a53b937c /drivers/tty
parent9078204ca5c33ba20443a8623a41a68a9995a70d (diff)
serial: mvebu-uart: do not allow changing baudrate when uartclk is not available
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>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/mvebu-uart.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
index f3ecbcf495ee..1789a6651ec6 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: