@@ -557,6 +557,9 @@ static int serial8250_em485_init(struct uart_8250_port *p)
if (!p->em485)
return -ENOMEM;
+ if (uart_console(&p->port))
+ dev_warn(p->port.dev, "no atomic printing for rs485 consoles\n");
+
hrtimer_init(&p->em485->stop_tx_timer, CLOCK_MONOTONIC,
HRTIMER_MODE_REL);
hrtimer_init(&p->em485->start_tx_timer, CLOCK_MONOTONIC,
@@ -709,17 +712,23 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
serial8250_rpm_put(p);
}
-static void serial8250_clear_IER(struct uart_8250_port *up)
+/* Only to be used by write_atomic(), which does not require port lock. */
+static void __serial8250_clear_IER(struct uart_8250_port *up)
{
- /* Port locked to synchronize UART_IER access against the console. */
- lockdep_assert_held_once(&up->port.lock);
-
if (up->capabilities & UART_CAP_UUE)
serial_out(up, UART_IER, UART_IER_UUE);
else
serial_out(up, UART_IER, 0);
}
+static inline void serial8250_clear_IER(struct uart_8250_port *up)
+{
+ /* Port locked to synchronize UART_IER access against the console. */
+ lockdep_assert_held_once(&up->port.lock);
+
+ __serial8250_clear_IER(up);
+}
+
#ifdef CONFIG_SERIAL_8250_RSA
/*
* Attempts to turn on the RSA FIFO. Returns zero on failure.
@@ -3397,15 +3406,18 @@ static void serial8250_console_fifo_write(struct uart_8250_port *up,
* Doing runtime PM is really a bad idea for the kernel console.
* Thus, we assume the function is called when device is powered up.
*/
-static void __serial8250_console_write(struct uart_8250_port *up, const char *s,
- unsigned int count)
+void serial8250_console_write(struct uart_8250_port *up, const char *s,
+ unsigned int count)
{
struct uart_8250_em485 *em485 = up->em485;
struct uart_port *port = &up->port;
+ unsigned long flags;
unsigned int ier, use_fifo;
touch_nmi_watchdog();
+ uart_port_lock_irqsave(port, &flags);
+
/*
* First save the IER then disable the interrupts
*/
@@ -3472,17 +3484,6 @@ static void __serial8250_console_write(struct uart_8250_port *up, const char *s,
*/
if (up->msr_saved_flags)
serial8250_modem_status(up);
-}
-
-void serial8250_console_write(struct uart_8250_port *up, const char *s,
- unsigned int count)
-{
- struct uart_port *port = &up->port;
- unsigned long flags;
-
- uart_port_lock_irqsave(port, &flags);
-
- __serial8250_console_write(up, s, count);
uart_port_unlock_irqrestore(port, flags);
}
@@ -3490,10 +3491,43 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
bool serial8250_console_write_atomic(struct uart_8250_port *up,
struct nbcon_write_context *wctxt)
{
+ struct uart_port *port = &up->port;
+ unsigned int ier;
+
+ /* Atomic console not supported for rs485 mode. */
+ if (up->em485)
+ return false;
+
+ /* Atomic console does not support handling modem control. */
+ if (up->msr_saved_flags)
+ return false;
+
+ touch_nmi_watchdog();
+
if (!nbcon_enter_unsafe(wctxt))
return false;
- __serial8250_console_write(up, wctxt->outbuf, wctxt->len);
+ /*
+ * First save the IER then disable the interrupts
+ */
+ ier = serial_port_in(port, UART_IER);
+ __serial8250_clear_IER(up);
+
+ /* check scratch reg to see if port powered off during system sleep */
+ if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) {
+ serial8250_console_restore(up);
+ up->canary = 0;
+ }
+
+ uart_console_write(port, wctxt->outbuf, wctxt->len, serial8250_console_putchar);
+
+ /*
+ * Finally, wait for transmitter to become empty
+ * and restore the IER
+ */
+ wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
+
+ serial_port_out(port, UART_IER, ier);
return nbcon_exit_unsafe(wctxt);
}
@@ -2335,7 +2335,7 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
if (uap->port.sysrq || oops_in_progress)
locked = uart_port_trylock_irqsave(&uap->port, &flags);
else
- uart_port_trylock_irqsave(&uap->port, &flags);
+ uart_port_lock_irqsave(&uap->port, &flags);
/*
* First save the CR then disable the interrupts
@@ -870,6 +870,7 @@ EXPORT_SYMBOL_GPL(nbcon_exit_unsafe);
/**
* nbcon_emit_next_record - Emit a record in the acquired context
* @wctxt: The write context that will be handed to the write function
+ * @in_kthread: True if called from kthread printer context.
*
* Return: True if this context still owns the console. False if
* ownership was handed over or taken.
@@ -1 +1 @@
--rt7
+-rt8
Dear RT folks! I'm pleased to announce the v6.6-rc4-rt8 patch set. Changes since v6.6-rc4-rt7: - The amba-pl011 acciently used a trylock instead of a normal lock operation for console output. This has been introduced in the previous release. Reported by Pierre Gondois. - The 8250 atomic console implementation used a bit of code which was not designed for atomic consoles. Reported by Pierre Gondois, patch by John Ogness. Known issues None The delta patch against v6.6-rc4-rt7 is appended below and can be found here: https://cdn.kernel.org/pub/linux/kernel/projects/rt/6.6/incr/patch-6.6-rc4-rt7-rt8.patch.xz You can get this release via the git tree at: https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git v6.6-rc4-rt8 The RT patch against v6.6-rc4 can be found here: https://cdn.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patch-6.6-rc4-rt8.patch.xz The split quilt queue is available at: https://cdn.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6-rc4-rt8.tar.xz Sebastian