Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> writes: > On 05.04.2024 09:56:37, Esben Haabendal wrote: >> By waiting at most 1 second for USR2_TXDC to be set, we avoid a potentital >> 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@xxxxxxxxxx> > > For the next round you should consult "scripts/get_maintainer.pl > drivers/tty/serial/imx.c" and add these people/lists on Cc. Yes. The idea was to do the RFC here on linux-rt, with focus on the 2nd patch in the series. When that is in good shape, I will send the first patch separately to all the proper maintainers and lists. >> --- >> drivers/tty/serial/imx.c | 7 ++++--- >> 1 file changed, 4 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c >> index 54b760d845c0..f7e4f38f08f3 100644 >> --- a/drivers/tty/serial/imx.c >> +++ b/drivers/tty/serial/imx.c >> @@ -26,6 +26,7 @@ >> #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> >> @@ -1995,7 +1996,7 @@ 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) >> @@ -2026,8 +2027,8 @@ 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, 1000000, false, sport, USR2); > > You can make use of USEC_PER_SEC here. > > After fixing this, feel free to add my: > > Acked-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Thanks. /Esben
