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| author |   Sergey Organov <sorganov@gmail.com> | 2019-08-28 21:37:51 +0300 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-09-04 12:43:55 +0200 |
| commit | 2eda5345e4ef61b35101b4fef58417a41d8d53fd (patch) | |
| tree | 0b0cfa5dca79ed8ab82a0ca1f91a8e336c401bfa /drivers/tty | |
| parent | tty: max310x: fix off-by-one buffer access when storing overrun (diff) | |
| download | linux-dev-2eda5345e4ef61b35101b4fef58417a41d8d53fd.tar.xz linux-dev-2eda5345e4ef61b35101b4fef58417a41d8d53fd.zip | |
serial: imx: get rid of unbounded busy-waiting loop
imx_set_termios(): remove busy-waiting "drain Tx FIFO" loop. Worse
yet, it was potentially unbounded wait due to RTS/CTS (hardware)
handshake.
Let user space ensure draining is done before termios change, if
draining is needed in the first place.
Signed-off-by: Sergey Organov <sorganov@gmail.com>
Link: https://lore.kernel.org/r/1567017475-11919-2-git-send-email-sorganov@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/imx.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index d9a73c7683ea..47b6156f5b2c 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1644,7 +1644,7 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios, uart_update_timeout(port, termios->c_cflag, baud); /* - * disable interrupts and drain transmitter + * disable interrupts */ old_ucr1 = imx_uart_readl(sport, UCR1); imx_uart_writel(sport, @@ -1652,9 +1652,6 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios, UCR1); imx_uart_writel(sport, old_ucr2 & ~UCR2_ATEN, UCR2); - while (!(imx_uart_readl(sport, USR2) & USR2_TXDC)) - barrier(); - /* then, disable everything */ imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN | UCR2_ATEN), UCR2); |