* [PATCH 1/3] serial: 8250: fix racy uartclk update
2021-10-15 11:14 [PATCH 0/3] serial: 8250: fix racy uartclk update Johan Hovold
@ 2021-10-15 11:14 ` Johan Hovold
2021-10-15 14:23 ` Andy Shevchenko
2021-10-15 11:14 ` [PATCH 2/3] serial: 8250: rename unlock labels Johan Hovold
` (2 subsequent siblings)
3 siblings, 1 reply; 11+ messages in thread
From: Johan Hovold @ 2021-10-15 11:14 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Jiri Slaby, Andy Shevchenko, Serge Semin, linux-serial,
linux-kernel, Johan Hovold, stable
Commit 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method")
added a hack to support SoCs where the UART reference clock can
change behind the back of the driver but failed to add the proper
locking.
First, make sure to take a reference to the tty struct to avoid
dereferencing a NULL pointer if the clock change races with a hangup.
Second, the termios semaphore must be held during the update to prevent
a racing termios change.
Fixes: 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method")
Fixes: c8dff3aa8241 ("serial: 8250: Skip uninitialized TTY port baud rate update")
Cc: stable@vger.kernel.org # 5.9
Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/tty/serial/8250/8250_port.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 66374704747e..e4dd82fd7c2a 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2696,21 +2696,32 @@ static unsigned int serial8250_get_baud_rate(struct uart_port *port,
void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
{
struct uart_8250_port *up = up_to_u8250p(port);
+ struct tty_port *tport = &port->state->port;
unsigned int baud, quot, frac = 0;
struct ktermios *termios;
+ struct tty_struct *tty;
unsigned long flags;
- mutex_lock(&port->state->port.mutex);
+ tty = tty_port_tty_get(tport);
+ if (!tty) {
+ mutex_lock(&tport->mutex);
+ port->uartclk = uartclk;
+ mutex_unlock(&tport->mutex);
+ return;
+ }
+
+ down_write(&tty->termios_rwsem);
+ mutex_lock(&tport->mutex);
if (port->uartclk == uartclk)
goto out_lock;
port->uartclk = uartclk;
- if (!tty_port_initialized(&port->state->port))
+ if (!tty_port_initialized(tport))
goto out_lock;
- termios = &port->state->port.tty->termios;
+ termios = &tty->termios;
baud = serial8250_get_baud_rate(port, termios, NULL);
quot = serial8250_get_divisor(port, baud, &frac);
@@ -2727,7 +2738,9 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
serial8250_rpm_put(up);
out_lock:
- mutex_unlock(&port->state->port.mutex);
+ mutex_unlock(&tport->mutex);
+ up_write(&tty->termios_rwsem);
+ tty_kref_put(tty);
}
EXPORT_SYMBOL_GPL(serial8250_update_uartclk);
--
2.32.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH 1/3] serial: 8250: fix racy uartclk update
2021-10-15 11:14 ` [PATCH 1/3] " Johan Hovold
@ 2021-10-15 14:23 ` Andy Shevchenko
0 siblings, 0 replies; 11+ messages in thread
From: Andy Shevchenko @ 2021-10-15 14:23 UTC (permalink / raw)
To: Johan Hovold
Cc: Greg Kroah-Hartman, Jiri Slaby, Serge Semin, linux-serial,
linux-kernel, stable
On Fri, Oct 15, 2021 at 01:14:20PM +0200, Johan Hovold wrote:
> Commit 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method")
> added a hack to support SoCs where the UART reference clock can
> change behind the back of the driver but failed to add the proper
> locking.
>
> First, make sure to take a reference to the tty struct to avoid
> dereferencing a NULL pointer if the clock change races with a hangup.
>
> Second, the termios semaphore must be held during the update to prevent
> a racing termios change.
Nice catch!
Thanks, Johan, for fixing this!
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Fixes: 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method")
> Fixes: c8dff3aa8241 ("serial: 8250: Skip uninitialized TTY port baud rate update")
> Cc: stable@vger.kernel.org # 5.9
> Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
> drivers/tty/serial/8250/8250_port.c | 21 +++++++++++++++++----
> 1 file changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
> index 66374704747e..e4dd82fd7c2a 100644
> --- a/drivers/tty/serial/8250/8250_port.c
> +++ b/drivers/tty/serial/8250/8250_port.c
> @@ -2696,21 +2696,32 @@ static unsigned int serial8250_get_baud_rate(struct uart_port *port,
> void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
> {
> struct uart_8250_port *up = up_to_u8250p(port);
> + struct tty_port *tport = &port->state->port;
> unsigned int baud, quot, frac = 0;
> struct ktermios *termios;
> + struct tty_struct *tty;
> unsigned long flags;
>
> - mutex_lock(&port->state->port.mutex);
> + tty = tty_port_tty_get(tport);
> + if (!tty) {
> + mutex_lock(&tport->mutex);
> + port->uartclk = uartclk;
> + mutex_unlock(&tport->mutex);
> + return;
> + }
> +
> + down_write(&tty->termios_rwsem);
> + mutex_lock(&tport->mutex);
>
> if (port->uartclk == uartclk)
> goto out_lock;
>
> port->uartclk = uartclk;
>
> - if (!tty_port_initialized(&port->state->port))
> + if (!tty_port_initialized(tport))
> goto out_lock;
>
> - termios = &port->state->port.tty->termios;
> + termios = &tty->termios;
>
> baud = serial8250_get_baud_rate(port, termios, NULL);
> quot = serial8250_get_divisor(port, baud, &frac);
> @@ -2727,7 +2738,9 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
> serial8250_rpm_put(up);
>
> out_lock:
> - mutex_unlock(&port->state->port.mutex);
> + mutex_unlock(&tport->mutex);
> + up_write(&tty->termios_rwsem);
> + tty_kref_put(tty);
> }
> EXPORT_SYMBOL_GPL(serial8250_update_uartclk);
>
> --
> 2.32.0
>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 2/3] serial: 8250: rename unlock labels
2021-10-15 11:14 [PATCH 0/3] serial: 8250: fix racy uartclk update Johan Hovold
2021-10-15 11:14 ` [PATCH 1/3] " Johan Hovold
@ 2021-10-15 11:14 ` Johan Hovold
2021-10-15 14:24 ` Andy Shevchenko
2021-10-16 15:40 ` Serge Semin
2021-10-15 11:14 ` [PATCH 3/3] serial: 8250_dw: drop bogus uartclk optimisation Johan Hovold
2021-10-15 19:10 ` [PATCH 0/3] serial: 8250: fix racy uartclk update Serge Semin
3 siblings, 2 replies; 11+ messages in thread
From: Johan Hovold @ 2021-10-15 11:14 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Jiri Slaby, Andy Shevchenko, Serge Semin, linux-serial,
linux-kernel, Johan Hovold
Rename a couple of oddly named labels that are used to unlock before
returning after what they do (rather than after the context they are
used in) to improve readability.
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/tty/serial/8250/8250_port.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index e4dd82fd7c2a..5775cbff8f6e 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1338,7 +1338,7 @@ static void autoconfig(struct uart_8250_port *up)
up->tx_loadsz = uart_config[port->type].tx_loadsz;
if (port->type == PORT_UNKNOWN)
- goto out_lock;
+ goto out_unlock;
/*
* Reset the UART.
@@ -1355,7 +1355,7 @@ static void autoconfig(struct uart_8250_port *up)
else
serial_out(up, UART_IER, 0);
-out_lock:
+out_unlock:
spin_unlock_irqrestore(&port->lock, flags);
/*
@@ -2714,12 +2714,12 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
mutex_lock(&tport->mutex);
if (port->uartclk == uartclk)
- goto out_lock;
+ goto out_unlock;
port->uartclk = uartclk;
if (!tty_port_initialized(tport))
- goto out_lock;
+ goto out_unlock;
termios = &tty->termios;
@@ -2737,7 +2737,7 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
spin_unlock_irqrestore(&port->lock, flags);
serial8250_rpm_put(up);
-out_lock:
+out_unlock:
mutex_unlock(&tport->mutex);
up_write(&tty->termios_rwsem);
tty_kref_put(tty);
--
2.32.0
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH 2/3] serial: 8250: rename unlock labels
2021-10-15 11:14 ` [PATCH 2/3] serial: 8250: rename unlock labels Johan Hovold
@ 2021-10-15 14:24 ` Andy Shevchenko
2021-10-16 15:40 ` Serge Semin
1 sibling, 0 replies; 11+ messages in thread
From: Andy Shevchenko @ 2021-10-15 14:24 UTC (permalink / raw)
To: Johan Hovold
Cc: Greg Kroah-Hartman, Jiri Slaby, Serge Semin, linux-serial,
linux-kernel
On Fri, Oct 15, 2021 at 01:14:21PM +0200, Johan Hovold wrote:
> Rename a couple of oddly named labels that are used to unlock before
> returning after what they do (rather than after the context they are
> used in) to improve readability.
I'm on the same page with the label naming schema, hence
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
> drivers/tty/serial/8250/8250_port.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
> index e4dd82fd7c2a..5775cbff8f6e 100644
> --- a/drivers/tty/serial/8250/8250_port.c
> +++ b/drivers/tty/serial/8250/8250_port.c
> @@ -1338,7 +1338,7 @@ static void autoconfig(struct uart_8250_port *up)
> up->tx_loadsz = uart_config[port->type].tx_loadsz;
>
> if (port->type == PORT_UNKNOWN)
> - goto out_lock;
> + goto out_unlock;
>
> /*
> * Reset the UART.
> @@ -1355,7 +1355,7 @@ static void autoconfig(struct uart_8250_port *up)
> else
> serial_out(up, UART_IER, 0);
>
> -out_lock:
> +out_unlock:
> spin_unlock_irqrestore(&port->lock, flags);
>
> /*
> @@ -2714,12 +2714,12 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
> mutex_lock(&tport->mutex);
>
> if (port->uartclk == uartclk)
> - goto out_lock;
> + goto out_unlock;
>
> port->uartclk = uartclk;
>
> if (!tty_port_initialized(tport))
> - goto out_lock;
> + goto out_unlock;
>
> termios = &tty->termios;
>
> @@ -2737,7 +2737,7 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
> spin_unlock_irqrestore(&port->lock, flags);
> serial8250_rpm_put(up);
>
> -out_lock:
> +out_unlock:
> mutex_unlock(&tport->mutex);
> up_write(&tty->termios_rwsem);
> tty_kref_put(tty);
> --
> 2.32.0
>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/3] serial: 8250: rename unlock labels
2021-10-15 11:14 ` [PATCH 2/3] serial: 8250: rename unlock labels Johan Hovold
2021-10-15 14:24 ` Andy Shevchenko
@ 2021-10-16 15:40 ` Serge Semin
1 sibling, 0 replies; 11+ messages in thread
From: Serge Semin @ 2021-10-16 15:40 UTC (permalink / raw)
To: Johan Hovold
Cc: Serge Semin, Greg Kroah-Hartman, Jiri Slaby, Andy Shevchenko,
linux-serial, linux-kernel
On Fri, Oct 15, 2021 at 01:14:21PM +0200, Johan Hovold wrote:
> Rename a couple of oddly named labels that are used to unlock before
> returning after what they do (rather than after the context they are
> used in) to improve readability.
Initially I had the same thought in mind when was adding the update
clock method because normally I add the GOTO-target-related suffix for
the cleanup path. But in this case I decided to stick with the locally
selected naming scheme, since it also made sense in the meaning: "goto
Out_of_the_Lock". So in case of the autoconfig() method leaving the
"out_lock" label name was reasonable because the code program counter
jumps out of the locked section of the function while the "goto out"
jumps to out of the method itself.
-Serge
>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
> drivers/tty/serial/8250/8250_port.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
> index e4dd82fd7c2a..5775cbff8f6e 100644
> --- a/drivers/tty/serial/8250/8250_port.c
> +++ b/drivers/tty/serial/8250/8250_port.c
> @@ -1338,7 +1338,7 @@ static void autoconfig(struct uart_8250_port *up)
> up->tx_loadsz = uart_config[port->type].tx_loadsz;
>
> if (port->type == PORT_UNKNOWN)
> - goto out_lock;
> + goto out_unlock;
>
> /*
> * Reset the UART.
> @@ -1355,7 +1355,7 @@ static void autoconfig(struct uart_8250_port *up)
> else
> serial_out(up, UART_IER, 0);
>
> -out_lock:
> +out_unlock:
> spin_unlock_irqrestore(&port->lock, flags);
>
> /*
> @@ -2714,12 +2714,12 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
> mutex_lock(&tport->mutex);
>
> if (port->uartclk == uartclk)
> - goto out_lock;
> + goto out_unlock;
>
> port->uartclk = uartclk;
>
> if (!tty_port_initialized(tport))
> - goto out_lock;
> + goto out_unlock;
>
> termios = &tty->termios;
>
> @@ -2737,7 +2737,7 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
> spin_unlock_irqrestore(&port->lock, flags);
> serial8250_rpm_put(up);
>
> -out_lock:
> +out_unlock:
> mutex_unlock(&tport->mutex);
> up_write(&tty->termios_rwsem);
> tty_kref_put(tty);
> --
> 2.32.0
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 3/3] serial: 8250_dw: drop bogus uartclk optimisation
2021-10-15 11:14 [PATCH 0/3] serial: 8250: fix racy uartclk update Johan Hovold
2021-10-15 11:14 ` [PATCH 1/3] " Johan Hovold
2021-10-15 11:14 ` [PATCH 2/3] serial: 8250: rename unlock labels Johan Hovold
@ 2021-10-15 11:14 ` Johan Hovold
2021-10-15 14:25 ` Andy Shevchenko
2021-10-15 19:10 ` [PATCH 0/3] serial: 8250: fix racy uartclk update Serge Semin
3 siblings, 1 reply; 11+ messages in thread
From: Johan Hovold @ 2021-10-15 11:14 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Jiri Slaby, Andy Shevchenko, Serge Semin, linux-serial,
linux-kernel, Johan Hovold
The driver was updating the port uartclk before setting the new rate in
an attempt to avoid having the clock notifier redundantly update the
divisors.
The set_termios() callback is however called under the termios semaphore
and tty-port mutex so the worker scheduled by the clock notifier will
block in serial8250_update_uartclk() until the uartclk and divisors have
been updated anyway.
Drop the unnecessary swaps and incorrect comment and simply update the
uartclk field if the clock-rate change was successful.
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/tty/serial/8250/8250_dw.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index a3a0154da567..52e03dd0eb3b 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -338,15 +338,12 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
rate = clk_round_rate(d->clk, newrate);
if (rate > 0) {
/*
- * Premilinary set the uartclk to the new clock rate so the
- * clock update event handler caused by the clk_set_rate()
- * calling wouldn't actually update the UART divisor since
- * we about to do this anyway.
+ * Note that any clock-notifer worker will block in
+ * serial8250_update_uartclk() until we are done.
*/
- swap(p->uartclk, rate);
ret = clk_set_rate(d->clk, newrate);
- if (ret)
- swap(p->uartclk, rate);
+ if (!ret)
+ p->uartclk = rate;
}
clk_prepare_enable(d->clk);
--
2.32.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH 3/3] serial: 8250_dw: drop bogus uartclk optimisation
2021-10-15 11:14 ` [PATCH 3/3] serial: 8250_dw: drop bogus uartclk optimisation Johan Hovold
@ 2021-10-15 14:25 ` Andy Shevchenko
0 siblings, 0 replies; 11+ messages in thread
From: Andy Shevchenko @ 2021-10-15 14:25 UTC (permalink / raw)
To: Johan Hovold
Cc: Greg Kroah-Hartman, Jiri Slaby, Serge Semin, linux-serial,
linux-kernel
On Fri, Oct 15, 2021 at 01:14:22PM +0200, Johan Hovold wrote:
> The driver was updating the port uartclk before setting the new rate in
> an attempt to avoid having the clock notifier redundantly update the
> divisors.
>
> The set_termios() callback is however called under the termios semaphore
> and tty-port mutex so the worker scheduled by the clock notifier will
> block in serial8250_update_uartclk() until the uartclk and divisors have
> been updated anyway.
>
> Drop the unnecessary swaps and incorrect comment and simply update the
> uartclk field if the clock-rate change was successful.
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
> drivers/tty/serial/8250/8250_dw.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
> index a3a0154da567..52e03dd0eb3b 100644
> --- a/drivers/tty/serial/8250/8250_dw.c
> +++ b/drivers/tty/serial/8250/8250_dw.c
> @@ -338,15 +338,12 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
> rate = clk_round_rate(d->clk, newrate);
> if (rate > 0) {
> /*
> - * Premilinary set the uartclk to the new clock rate so the
> - * clock update event handler caused by the clk_set_rate()
> - * calling wouldn't actually update the UART divisor since
> - * we about to do this anyway.
> + * Note that any clock-notifer worker will block in
> + * serial8250_update_uartclk() until we are done.
> */
> - swap(p->uartclk, rate);
> ret = clk_set_rate(d->clk, newrate);
> - if (ret)
> - swap(p->uartclk, rate);
> + if (!ret)
> + p->uartclk = rate;
> }
> clk_prepare_enable(d->clk);
>
> --
> 2.32.0
>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 0/3] serial: 8250: fix racy uartclk update
2021-10-15 11:14 [PATCH 0/3] serial: 8250: fix racy uartclk update Johan Hovold
` (2 preceding siblings ...)
2021-10-15 11:14 ` [PATCH 3/3] serial: 8250_dw: drop bogus uartclk optimisation Johan Hovold
@ 2021-10-15 19:10 ` Serge Semin
2021-10-16 15:25 ` Serge Semin
3 siblings, 1 reply; 11+ messages in thread
From: Serge Semin @ 2021-10-15 19:10 UTC (permalink / raw)
To: Johan Hovold
Cc: Serge Semin, Greg Kroah-Hartman, Jiri Slaby, Andy Shevchenko,
linux-serial, linux-kernel
On Fri, Oct 15, 2021 at 01:14:19PM +0200, Johan Hovold wrote:
> Here's a fix for the asynchronous uartclk-update hack which was added
> last year and a couple of related clean ups.
Yeah, that was very unfortunate patchset. Thank you very much for the fix.
I'll test it out tomorrow.
-Sergey
>
> Johan
>
>
> Johan Hovold (3):
> serial: 8250: fix racy uartclk update
> serial: 8250: rename unlock labels
> serial: 8250_dw: drop bogus uartclk optimisation
>
> drivers/tty/serial/8250/8250_dw.c | 11 ++++------
> drivers/tty/serial/8250/8250_port.c | 31 ++++++++++++++++++++---------
> 2 files changed, 26 insertions(+), 16 deletions(-)
>
> --
> 2.32.0
>
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH 0/3] serial: 8250: fix racy uartclk update
2021-10-15 19:10 ` [PATCH 0/3] serial: 8250: fix racy uartclk update Serge Semin
@ 2021-10-16 15:25 ` Serge Semin
2021-10-18 6:29 ` Johan Hovold
0 siblings, 1 reply; 11+ messages in thread
From: Serge Semin @ 2021-10-16 15:25 UTC (permalink / raw)
To: Johan Hovold
Cc: Serge Semin, Greg Kroah-Hartman, Jiri Slaby, Andy Shevchenko,
linux-serial, linux-kernel
Hello Johan
On Fri, Oct 15, 2021 at 10:10:00PM +0300, Serge Semin wrote:
> On Fri, Oct 15, 2021 at 01:14:19PM +0200, Johan Hovold wrote:
> > Here's a fix for the asynchronous uartclk-update hack which was added
> > last year and a couple of related clean ups.
>
> Yeah, that was very unfortunate patchset. Thank you very much for the fix.
> I'll test it out tomorrow.
>
> -Sergey
The series has been tested on Baikal-T1 SoC with two UART ports
feed with a common reference clock. It's working well. Thanks again
for fixing the problem. For the whole series
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
-Sergey
>
> >
> > Johan
> >
> >
> > Johan Hovold (3):
> > serial: 8250: fix racy uartclk update
> > serial: 8250: rename unlock labels
> > serial: 8250_dw: drop bogus uartclk optimisation
> >
> > drivers/tty/serial/8250/8250_dw.c | 11 ++++------
> > drivers/tty/serial/8250/8250_port.c | 31 ++++++++++++++++++++---------
> > 2 files changed, 26 insertions(+), 16 deletions(-)
> >
> > --
> > 2.32.0
> >
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 0/3] serial: 8250: fix racy uartclk update
2021-10-16 15:25 ` Serge Semin
@ 2021-10-18 6:29 ` Johan Hovold
0 siblings, 0 replies; 11+ messages in thread
From: Johan Hovold @ 2021-10-18 6:29 UTC (permalink / raw)
To: Serge Semin
Cc: Serge Semin, Greg Kroah-Hartman, Jiri Slaby, Andy Shevchenko,
linux-serial, linux-kernel
On Sat, Oct 16, 2021 at 06:25:21PM +0300, Serge Semin wrote:
> The series has been tested on Baikal-T1 SoC with two UART ports
> feed with a common reference clock. It's working well. Thanks again
> for fixing the problem. For the whole series
> Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
> Tested-by: Serge Semin <fancer.lancer@gmail.com>
Thanks for testing.
Johan
^ permalink raw reply [flat|nested] 11+ messages in thread