diff options
| author | Pali Rohár <pali@kernel.org> | 2022-06-28 12:09:22 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-30 17:17:31 +0200 |
| commit | 4f532c1e25319e42996ec18a1f473fd50c8e575d (patch) | |
| tree | b5ba77cf5a79937b4dff33667665521878c2ade3 | |
| parent | f9b11229b79c0fb2100b5bb4628a101b1d37fbf6 (diff) | |
| download | linux-4f532c1e25319e42996ec18a1f473fd50c8e575d.tar.bz2 | |
serial: mvebu-uart: correctly report configured baudrate value
Functions tty_termios_encode_baud_rate() and uart_update_timeout() should
be called with the baudrate value which was set to hardware. Linux then
report exact values via ioctl(TCGETS2) to userspace.
Change mvebu_uart_baud_rate_set() function to return baudrate value which
was set to hardware and propagate this value to above mentioned functions.
With this change userspace would see precise value in termios c_ospeed
field.
Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate")
Cc: stable <stable@kernel.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20220628100922.10717-1-pali@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/mvebu-uart.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c index 0429c2a54290..93489fe334d0 100644 --- a/drivers/tty/serial/mvebu-uart.c +++ b/drivers/tty/serial/mvebu-uart.c @@ -470,14 +470,14 @@ static void mvebu_uart_shutdown(struct uart_port *port) } } -static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud) +static unsigned int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud) { unsigned int d_divisor, m_divisor; unsigned long flags; u32 brdv, osamp; if (!port->uartclk) - return -EOPNOTSUPP; + return 0; /* * The baudrate is derived from the UART clock thanks to divisors: @@ -548,7 +548,7 @@ static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud) (m_divisor << 16) | (m_divisor << 24); writel(osamp, port->membase + UART_OSAMP); - return 0; + return DIV_ROUND_CLOSEST(port->uartclk, d_divisor * m_divisor); } static void mvebu_uart_set_termios(struct uart_port *port, @@ -587,15 +587,11 @@ static void mvebu_uart_set_termios(struct uart_port *port, max_baud = port->uartclk / 80; baud = uart_get_baud_rate(port, termios, old, min_baud, max_baud); - if (mvebu_uart_baud_rate_set(port, baud)) { - /* No clock available, baudrate cannot be changed */ - if (old) - baud = uart_get_baud_rate(port, old, NULL, - min_baud, max_baud); - } else { - tty_termios_encode_baud_rate(termios, baud, baud); - uart_update_timeout(port, termios->c_cflag, baud); - } + baud = mvebu_uart_baud_rate_set(port, baud); + + /* In case baudrate cannot be changed, report previous old value */ + if (baud == 0 && old) + baud = tty_termios_baud_rate(old); /* Only the following flag changes are supported */ if (old) { @@ -606,6 +602,11 @@ static void mvebu_uart_set_termios(struct uart_port *port, termios->c_cflag |= CS8; } + if (baud != 0) { + tty_termios_encode_baud_rate(termios, baud, baud); + uart_update_timeout(port, termios->c_cflag, baud); + } + spin_unlock_irqrestore(&port->lock, flags); } |