From: pkrasavin@imaqliq.ru
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
Neil Armstrong <neil.armstrong@linaro.org>,
Kevin Hilman <khilman@baylibre.com>,
Jerome Brunet <jbrunet@baylibre.com>,
Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-amlogic@lists.infradead.org
Subject: [PATCH v2] tty: serial: meson: hard LOCKUP on crtscts mode
Date: Thu, 12 Oct 2023 13:22:41 +0000 [thread overview]
Message-ID: <OF950BEF72.7F425944-ON00258A46.00488A76-00258A46.00497D44@gdc.ru> (raw)
In-Reply-To:
There might be hard lockup if we set crtscts mode on port without RTS/CTS configured:
# stty -F /dev/ttyAML6 crtscts; echo 1 > /dev/ttyAML6; echo 2 > /dev/ttyAML6
[ 95.890386] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[ 95.890857] rcu: 3-...0: (201 ticks this GP) idle=e33c/1/0x4000000000000000 softirq=5844/5846 fqs=4984
[ 95.900212] rcu: (detected by 2, t=21016 jiffies, g=7753, q=296 ncpus=4)
[ 95.906972] Task dump for CPU 3:
[ 95.910178] task:bash state:R running task stack:0 pid:205 ppid:1 flags:0x00000202
[ 95.920059] Call trace:
[ 95.922485] __switch_to+0xe4/0x168
[ 95.925951] 0xffffff8003477508
[ 95.974379] watchdog: Watchdog detected hard LOCKUP on cpu 3
[ 95.974424] Modules linked in: 88x2cs(O) rtc_meson_vrtc
Possible solution would be to not allow to setup crtscts on such port.
Tested on S905X3 based board.
Signed-off-by: Pavel Krasavin <pkrasavin@imaqliq.com>
---
v2: braces for single statement removed according to Dmitry's note
v1: https://lore.kernel.org/lkml/OF28B2B8C9.5BC0CD28-ON00258A46.0037688F-00258A46.0039155B@gdc.ru/
---
--- a/drivers/tty/serial/meson_uart.c 2023-10-12 15:44:02.410538523 +0300
+++ b/drivers/tty/serial/meson_uart.c 2023-10-12 15:58:06.242395253 +0300
@@ -380,10 +380,14 @@ static void meson_uart_set_termios(struc
else
val |= AML_UART_STOP_BIT_1SB;
- if (cflags & CRTSCTS)
- val &= ~AML_UART_TWO_WIRE_EN;
- else
+ if (cflags & CRTSCTS) {
+ if (port->flags & UPF_HARD_FLOW)
+ val &= ~AML_UART_TWO_WIRE_EN;
+ else
+ termios->c_cflag &= ~CRTSCTS;
+ } else {
val |= AML_UART_TWO_WIRE_EN;
+ }
writel(val, port->membase + AML_UART_CONTROL);
@@ -705,6 +709,7 @@ static int meson_uart_probe(struct platf
u32 fifosize = 64; /* Default is 64, 128 for EE UART_0 */
int ret = 0;
int irq;
+ bool has_rtscts;
if (pdev->dev.of_node)
pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
@@ -732,6 +737,7 @@ static int meson_uart_probe(struct platf
return irq;
of_property_read_u32(pdev->dev.of_node, "fifo-size", &fifosize);
+ has_rtscts = of_property_read_bool(pdev->dev.of_node, "uart-has-rtscts");
if (meson_ports[pdev->id]) {
return dev_err_probe(&pdev->dev, -EBUSY,
@@ -762,6 +768,8 @@ static int meson_uart_probe(struct platf
port->mapsize = resource_size(res_mem);
port->irq = irq;
port->flags = UPF_BOOT_AUTOCONF | UPF_LOW_LATENCY;
+ if (has_rtscts)
+ port->flags |= UPF_HARD_FLOW;
port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MESON_CONSOLE);
port->dev = &pdev->dev;
port->line = pdev->id;
WARNING: multiple messages have this Message-ID (diff)
From: pkrasavin@imaqliq.ru
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
Neil Armstrong <neil.armstrong@linaro.org>,
Kevin Hilman <khilman@baylibre.com>,
Jerome Brunet <jbrunet@baylibre.com>,
Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-amlogic@lists.infradead.org
Subject: [PATCH v2] tty: serial: meson: hard LOCKUP on crtscts mode
Date: Thu, 12 Oct 2023 13:22:41 +0000 [thread overview]
Message-ID: <OF950BEF72.7F425944-ON00258A46.00488A76-00258A46.00497D44@gdc.ru> (raw)
In-Reply-To:
There might be hard lockup if we set crtscts mode on port without RTS/CTS configured:
# stty -F /dev/ttyAML6 crtscts; echo 1 > /dev/ttyAML6; echo 2 > /dev/ttyAML6
[ 95.890386] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[ 95.890857] rcu: 3-...0: (201 ticks this GP) idle=e33c/1/0x4000000000000000 softirq=5844/5846 fqs=4984
[ 95.900212] rcu: (detected by 2, t=21016 jiffies, g=7753, q=296 ncpus=4)
[ 95.906972] Task dump for CPU 3:
[ 95.910178] task:bash state:R running task stack:0 pid:205 ppid:1 flags:0x00000202
[ 95.920059] Call trace:
[ 95.922485] __switch_to+0xe4/0x168
[ 95.925951] 0xffffff8003477508
[ 95.974379] watchdog: Watchdog detected hard LOCKUP on cpu 3
[ 95.974424] Modules linked in: 88x2cs(O) rtc_meson_vrtc
Possible solution would be to not allow to setup crtscts on such port.
Tested on S905X3 based board.
Signed-off-by: Pavel Krasavin <pkrasavin@imaqliq.com>
---
v2: braces for single statement removed according to Dmitry's note
v1: https://lore.kernel.org/lkml/OF28B2B8C9.5BC0CD28-ON00258A46.0037688F-00258A46.0039155B@gdc.ru/
---
--- a/drivers/tty/serial/meson_uart.c 2023-10-12 15:44:02.410538523 +0300
+++ b/drivers/tty/serial/meson_uart.c 2023-10-12 15:58:06.242395253 +0300
@@ -380,10 +380,14 @@ static void meson_uart_set_termios(struc
else
val |= AML_UART_STOP_BIT_1SB;
- if (cflags & CRTSCTS)
- val &= ~AML_UART_TWO_WIRE_EN;
- else
+ if (cflags & CRTSCTS) {
+ if (port->flags & UPF_HARD_FLOW)
+ val &= ~AML_UART_TWO_WIRE_EN;
+ else
+ termios->c_cflag &= ~CRTSCTS;
+ } else {
val |= AML_UART_TWO_WIRE_EN;
+ }
writel(val, port->membase + AML_UART_CONTROL);
@@ -705,6 +709,7 @@ static int meson_uart_probe(struct platf
u32 fifosize = 64; /* Default is 64, 128 for EE UART_0 */
int ret = 0;
int irq;
+ bool has_rtscts;
if (pdev->dev.of_node)
pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
@@ -732,6 +737,7 @@ static int meson_uart_probe(struct platf
return irq;
of_property_read_u32(pdev->dev.of_node, "fifo-size", &fifosize);
+ has_rtscts = of_property_read_bool(pdev->dev.of_node, "uart-has-rtscts");
if (meson_ports[pdev->id]) {
return dev_err_probe(&pdev->dev, -EBUSY,
@@ -762,6 +768,8 @@ static int meson_uart_probe(struct platf
port->mapsize = resource_size(res_mem);
port->irq = irq;
port->flags = UPF_BOOT_AUTOCONF | UPF_LOW_LATENCY;
+ if (has_rtscts)
+ port->flags |= UPF_HARD_FLOW;
port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MESON_CONSOLE);
port->dev = &pdev->dev;
port->line = pdev->id;
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: pkrasavin@imaqliq.ru
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
Neil Armstrong <neil.armstrong@linaro.org>,
Kevin Hilman <khilman@baylibre.com>,
Jerome Brunet <jbrunet@baylibre.com>,
Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-amlogic@lists.infradead.org
Subject: [PATCH v2] tty: serial: meson: hard LOCKUP on crtscts mode
Date: Thu, 12 Oct 2023 13:22:41 +0000 [thread overview]
Message-ID: <OF950BEF72.7F425944-ON00258A46.00488A76-00258A46.00497D44@gdc.ru> (raw)
In-Reply-To:
There might be hard lockup if we set crtscts mode on port without RTS/CTS configured:
# stty -F /dev/ttyAML6 crtscts; echo 1 > /dev/ttyAML6; echo 2 > /dev/ttyAML6
[ 95.890386] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[ 95.890857] rcu: 3-...0: (201 ticks this GP) idle=e33c/1/0x4000000000000000 softirq=5844/5846 fqs=4984
[ 95.900212] rcu: (detected by 2, t=21016 jiffies, g=7753, q=296 ncpus=4)
[ 95.906972] Task dump for CPU 3:
[ 95.910178] task:bash state:R running task stack:0 pid:205 ppid:1 flags:0x00000202
[ 95.920059] Call trace:
[ 95.922485] __switch_to+0xe4/0x168
[ 95.925951] 0xffffff8003477508
[ 95.974379] watchdog: Watchdog detected hard LOCKUP on cpu 3
[ 95.974424] Modules linked in: 88x2cs(O) rtc_meson_vrtc
Possible solution would be to not allow to setup crtscts on such port.
Tested on S905X3 based board.
Signed-off-by: Pavel Krasavin <pkrasavin@imaqliq.com>
---
v2: braces for single statement removed according to Dmitry's note
v1: https://lore.kernel.org/lkml/OF28B2B8C9.5BC0CD28-ON00258A46.0037688F-00258A46.0039155B@gdc.ru/
---
--- a/drivers/tty/serial/meson_uart.c 2023-10-12 15:44:02.410538523 +0300
+++ b/drivers/tty/serial/meson_uart.c 2023-10-12 15:58:06.242395253 +0300
@@ -380,10 +380,14 @@ static void meson_uart_set_termios(struc
else
val |= AML_UART_STOP_BIT_1SB;
- if (cflags & CRTSCTS)
- val &= ~AML_UART_TWO_WIRE_EN;
- else
+ if (cflags & CRTSCTS) {
+ if (port->flags & UPF_HARD_FLOW)
+ val &= ~AML_UART_TWO_WIRE_EN;
+ else
+ termios->c_cflag &= ~CRTSCTS;
+ } else {
val |= AML_UART_TWO_WIRE_EN;
+ }
writel(val, port->membase + AML_UART_CONTROL);
@@ -705,6 +709,7 @@ static int meson_uart_probe(struct platf
u32 fifosize = 64; /* Default is 64, 128 for EE UART_0 */
int ret = 0;
int irq;
+ bool has_rtscts;
if (pdev->dev.of_node)
pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
@@ -732,6 +737,7 @@ static int meson_uart_probe(struct platf
return irq;
of_property_read_u32(pdev->dev.of_node, "fifo-size", &fifosize);
+ has_rtscts = of_property_read_bool(pdev->dev.of_node, "uart-has-rtscts");
if (meson_ports[pdev->id]) {
return dev_err_probe(&pdev->dev, -EBUSY,
@@ -762,6 +768,8 @@ static int meson_uart_probe(struct platf
port->mapsize = resource_size(res_mem);
port->irq = irq;
port->flags = UPF_BOOT_AUTOCONF | UPF_LOW_LATENCY;
+ if (has_rtscts)
+ port->flags |= UPF_HARD_FLOW;
port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MESON_CONSOLE);
port->dev = &pdev->dev;
port->line = pdev->id;
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
next reply other threads:[~2023-10-12 13:22 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-12 13:22 pkrasavin [this message]
2023-10-12 13:22 ` [PATCH v2] tty: serial: meson: hard LOCKUP on crtscts mode pkrasavin
2023-10-12 13:22 ` pkrasavin
2023-10-12 13:30 ` Greg Kroah-Hartman
2023-10-12 13:30 ` Greg Kroah-Hartman
2023-10-12 13:30 ` Greg Kroah-Hartman
2023-10-13 10:43 ` Jiri Slaby
2023-10-13 10:43 ` Jiri Slaby
2023-10-13 10:43 ` Jiri Slaby
2023-10-13 11:09 ` Pavel Krasavin
2023-10-13 11:09 ` Pavel Krasavin
2023-10-13 11:09 ` Pavel Krasavin
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