From: John Ogness <john.ogness@linutronix.de>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Dick Hollenbeck <dick@softplc.com>,
linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org
Subject: [PATCH RT 2/2] serial: 8250: fsl/ingenic/mtk: fix atomic console
Date: Fri, 10 Jan 2020 16:45:32 +0106 [thread overview]
Message-ID: <20200110153932.14970-3-john.ogness@linutronix.de> (raw)
In-Reply-To: <20200110153932.14970-1-john.ogness@linutronix.de>
A few 8250 implementations have their own IER access. If the port
is a console, wrap the accesses with console_atomic_lock.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
drivers/tty/serial/8250/8250_fsl.c | 9 ++++++++
drivers/tty/serial/8250/8250_ingenic.c | 7 +++++++
drivers/tty/serial/8250/8250_mtk.c | 29 ++++++++++++++++++++++++--
3 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c
index aa0e216d5ead..8f711afadd4b 100644
--- a/drivers/tty/serial/8250/8250_fsl.c
+++ b/drivers/tty/serial/8250/8250_fsl.c
@@ -57,9 +57,18 @@ int fsl8250_handle_irq(struct uart_port *port)
/* Stop processing interrupts on input overrun */
if ((orig_lsr & UART_LSR_OE) && (up->overrun_backoff_time_ms > 0)) {
+ unsigned int ca_flags;
unsigned long delay;
+ bool is_console;
+ is_console = uart_console(port);
+
+ if (is_console)
+ console_atomic_lock(&ca_flags);
up->ier = port->serial_in(port, UART_IER);
+ if (is_console)
+ console_atomic_unlock(ca_flags);
+
if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
port->ops->stop_rx(port);
} else {
diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c
index 424c07c5f629..47f1482bd818 100644
--- a/drivers/tty/serial/8250/8250_ingenic.c
+++ b/drivers/tty/serial/8250/8250_ingenic.c
@@ -146,6 +146,8 @@ OF_EARLYCON_DECLARE(x1000_uart, "ingenic,x1000-uart",
static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value)
{
+ unsigned int flags;
+ bool is_console;
int ier;
switch (offset) {
@@ -167,7 +169,12 @@ static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value)
* If we have enabled modem status IRQs we should enable
* modem mode.
*/
+ is_console = uart_console(p);
+ if (is_console)
+ console_atomic_lock(&flags);
ier = p->serial_in(p, UART_IER);
+ if (is_console)
+ console_atomic_unlock(flags);
if (ier & UART_IER_MSI)
value |= UART_MCR_MDCE | UART_MCR_FCM;
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 4d067f515f74..b509c3de0301 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -212,12 +212,37 @@ static void mtk8250_shutdown(struct uart_port *port)
static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)
{
- serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask));
+ struct uart_port *port = &up->port;
+ unsigned int flags;
+ unsigned int ier;
+ bool is_console;
+
+ is_console = uart_console(port);
+
+ if (is_console)
+ console_atomic_lock(&flags);
+
+ ier = serial_in(up, UART_IER);
+ serial_out(up, UART_IER, ier & (~mask));
+
+ if (is_console)
+ console_atomic_unlock(flags);
}
static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask)
{
- serial_out(up, UART_IER, serial_in(up, UART_IER) | mask);
+ struct uart_port *port = &up->port;
+ unsigned int flags;
+ unsigned int ier;
+
+ if (uart_console(port))
+ console_atomic_lock(&flags);
+
+ ier = serial_in(up, UART_IER);
+ serial_out(up, UART_IER, ier | mask);
+
+ if (uart_console(port))
+ console_atomic_unlock(flags);
}
static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
--
2.20.1
next prev parent reply other threads:[~2020-01-10 15:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-10 15:39 [PATCH RT 0/2] serial: 8250: atomic console fixups John Ogness
2020-01-10 15:39 ` [PATCH RT 1/2] serial: 8250: only atomic lock for console John Ogness
2020-01-10 15:39 ` John Ogness [this message]
2020-01-10 17:36 ` [PATCH RT 0/2] serial: 8250: atomic console fixups Dick Hollenbeck
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