diff options
| author | Esben Haabendal <esben@geanix.com> | 2024-04-11 14:19:23 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-17 13:13:57 +0200 |
| commit | e533e4c62e9993e62e947ae9bbec34e4c7ae81c2 (patch) | |
| tree | 1919ce2533e8e432eb4bf432d3a000abefb86ca1 /drivers/tty/serial/imx.c | |
| parent | abcd8632f26bbc24c4364b9cdf4feb8c9828c0c6 (diff) | |
| download | lwn-e533e4c62e9993e62e947ae9bbec34e4c7ae81c2.tar.gz lwn-e533e4c62e9993e62e947ae9bbec34e4c7ae81c2.zip | |
serial: imx: Introduce timeout when waiting on transmitter empty
By waiting at most 1 second for USR2_TXDC to be set, we avoid a potential
deadlock.
In case of the timeout, there is not much we can do, so we simply ignore
the transmitter state and optimistically try to continue.
Signed-off-by: Esben Haabendal <esben@geanix.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/r/919647898c337a46604edcabaf13d42d80c0915d.1712837613.git.esben@geanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/imx.c')
| -rw-r--r-- | drivers/tty/serial/imx.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 56b76a221082..79f1503cd75b 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -27,6 +27,7 @@ #include <linux/slab.h> #include <linux/of.h> #include <linux/io.h> +#include <linux/iopoll.h> #include <linux/dma-mapping.h> #include <asm/irq.h> @@ -2002,7 +2003,7 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count) struct imx_port *sport = imx_uart_ports[co->index]; struct imx_port_ucrs old_ucr; unsigned long flags; - unsigned int ucr1; + unsigned int ucr1, usr2; int locked = 1; if (sport->port.sysrq) @@ -2033,8 +2034,8 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count) * Finally, wait for transmitter to become empty * and restore UCR1/2/3 */ - while (!(imx_uart_readl(sport, USR2) & USR2_TXDC)); - + read_poll_timeout_atomic(imx_uart_readl, usr2, usr2 & USR2_TXDC, + 0, USEC_PER_SEC, false, sport, USR2); imx_uart_ucrs_restore(sport, &old_ucr); if (locked) |