| Message ID | 919647898c337a46604edcabaf13d42d80c0915d.1712837613.git.esben@geanix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] serial: imx: Introduce timeout when waiting on transmitter empty | expand |
Esben Haabendal <esben@geanix.com> writes: > 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> > --- > > v2: > - Fixed commit message typo > - Remove reference to patch series it originated from. This is a > stand-alone patch > > v3: > - Moved this version information into the correct patch section Anything more needed in order to get this merged? /Esben > > 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 e14813250616..09c1678ddfd4 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> > @@ -2010,7 +2011,7 @@ 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) > @@ -2041,8 +2042,8 @@ 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)
On Thu, May 02, 2024 at 11:14:26AM +0200, Esben Haabendal wrote: > Esben Haabendal <esben@geanix.com> writes: > > > 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> > > --- > > > > v2: > > - Fixed commit message typo > > - Remove reference to patch series it originated from. This is a > > stand-alone patch > > > > v3: > > - Moved this version information into the correct patch section > > Anything more needed in order to get this merged? Sorry, but I don't see this in my review queue anymore. If this isn't already accepted, please resend it, sorry about that. greg k-h
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index e14813250616..09c1678ddfd4 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> @@ -2010,7 +2011,7 @@ 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) @@ -2041,8 +2042,8 @@ 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)