The only user of the start_rx() callback (qcom_geni) directly calls
its own stop_rx() callback. Since stop_rx() requires that the
port->lock is taken and interrupts are disabled, the start_rx()
callback has the same requirement.
Fixes: cfab87c2c271 ("serial: core: Introduce callback for start_rx and do stop_rx in suspend only if this callback implementation is present.")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
drivers/tty/serial/serial_core.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 37ad53616372..f856c7fae2fd 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2430,8 +2430,11 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
if (console_suspend_enabled)
uart_change_pm(state, UART_PM_STATE_ON);
uport->ops->set_termios(uport, &termios, NULL);
- if (!console_suspend_enabled && uport->ops->start_rx)
+ if (!console_suspend_enabled && uport->ops->start_rx) {
+ spin_lock_irq(&uport->lock);
uport->ops->start_rx(uport);
+ spin_unlock_irq(&uport->lock);
+ }
if (console_suspend_enabled)
console_start(uport->cons);
}
--
2.30.2
Hi, On Thu, May 25, 2023 at 2:34 AM John Ogness <john.ogness@linutronix.de> wrote: > > The only user of the start_rx() callback (qcom_geni) directly calls > its own stop_rx() callback. Since stop_rx() requires that the > port->lock is taken and interrupts are disabled, the start_rx() > callback has the same requirement. > > Fixes: cfab87c2c271 ("serial: core: Introduce callback for start_rx and do stop_rx in suspend only if this callback implementation is present.") > Signed-off-by: John Ogness <john.ogness@linutronix.de> > --- > drivers/tty/serial/serial_core.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c > index 37ad53616372..f856c7fae2fd 100644 > --- a/drivers/tty/serial/serial_core.c > +++ b/drivers/tty/serial/serial_core.c > @@ -2430,8 +2430,11 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) > if (console_suspend_enabled) > uart_change_pm(state, UART_PM_STATE_ON); > uport->ops->set_termios(uport, &termios, NULL); > - if (!console_suspend_enabled && uport->ops->start_rx) > + if (!console_suspend_enabled && uport->ops->start_rx) { > + spin_lock_irq(&uport->lock); > uport->ops->start_rx(uport); > + spin_unlock_irq(&uport->lock); > + } Seems right, but shouldn't you also fix the call to stop_rx() that the same commit cfab87c2c271 ("serial: core: Introduce callback for start_rx and do stop_rx in suspend only if this callback implementation is present.") added? That one is also missing the lock, right? -Doug
Hi, On Thu, May 25, 2023 at 9:07 AM Doug Anderson <dianders@chromium.org> wrote: > > Hi, > > On Thu, May 25, 2023 at 2:34 AM John Ogness <john.ogness@linutronix.de> wrote: > > > > The only user of the start_rx() callback (qcom_geni) directly calls > > its own stop_rx() callback. Since stop_rx() requires that the > > port->lock is taken and interrupts are disabled, the start_rx() > > callback has the same requirement. > > > > Fixes: cfab87c2c271 ("serial: core: Introduce callback for start_rx and do stop_rx in suspend only if this callback implementation is present.") > > Signed-off-by: John Ogness <john.ogness@linutronix.de> > > --- > > drivers/tty/serial/serial_core.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c > > index 37ad53616372..f856c7fae2fd 100644 > > --- a/drivers/tty/serial/serial_core.c > > +++ b/drivers/tty/serial/serial_core.c > > @@ -2430,8 +2430,11 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) > > if (console_suspend_enabled) > > uart_change_pm(state, UART_PM_STATE_ON); > > uport->ops->set_termios(uport, &termios, NULL); > > - if (!console_suspend_enabled && uport->ops->start_rx) > > + if (!console_suspend_enabled && uport->ops->start_rx) { > > + spin_lock_irq(&uport->lock); > > uport->ops->start_rx(uport); > > + spin_unlock_irq(&uport->lock); > > + } > > Seems right, but shouldn't you also fix the call to stop_rx() that the > same commit cfab87c2c271 ("serial: core: Introduce callback for > start_rx and do stop_rx in suspend only if this callback > implementation is present.") added? That one is also missing the lock, > right? Ah, I see. You did that in a separate patch and I wasn't CCed. I guess I would have just put the two in one patch, but I don't feel that strongly. Reviewed-by: Douglas Anderson <dianders@chromium.org>
On 2023-05-25, Doug Anderson <dianders@chromium.org> wrote: >> Seems right, but shouldn't you also fix the call to stop_rx() that >> the same commit cfab87c2c271 ("serial: core: Introduce callback for >> start_rx and do stop_rx in suspend only if this callback >> implementation is present.") added? That one is also missing the >> lock, right? > > Ah, I see. You did that in a separate patch and I wasn't CCed. I guess > I would have just put the two in one patch, but I don't feel that > strongly. Actually stop_rx() was introduced in a different commit. The commit you reference just changed it a bit. My other patch uses a different Fixes tag. Also, I was concerned about packing too much new spin locking in a single commit in the hopes it will help with any bisecting issues. > Reviewed-by: Douglas Anderson <dianders@chromium.org> Thanks! John
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