The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 3d732690d2267f4d0e19077b178dffbedafdf0c9 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Wed, 7 Apr 2021 12:39:16 +0200
Subject: [PATCH] USB: serial: usb_wwan: fix TIOCSSERIAL jiffies conversions
The port close_delay and closing_wait parameters set by TIOCSSERIAL are
specified in jiffies and not milliseconds.
Add the missing conversions so that the TIOCSSERIAL works as expected
also when HZ is not 1000.
Fixes: 02303f73373a ("usb-wwan: implement TIOCGSERIAL and TIOCSSERIAL to avoid blocking close(2)")
Cc: stable(a)vger.kernel.org # 2.6.38
Reviewed-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c
index 46d46a4f99c9..4e9c994a972a 100644
--- a/drivers/usb/serial/usb_wwan.c
+++ b/drivers/usb/serial/usb_wwan.c
@@ -140,10 +140,10 @@ int usb_wwan_get_serial_info(struct tty_struct *tty,
ss->line = port->minor;
ss->port = port->port_number;
ss->baud_base = tty_get_baud_rate(port->port.tty);
- ss->close_delay = port->port.close_delay / 10;
+ ss->close_delay = jiffies_to_msecs(port->port.close_delay) / 10;
ss->closing_wait = port->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
ASYNC_CLOSING_WAIT_NONE :
- port->port.closing_wait / 10;
+ jiffies_to_msecs(port->port.closing_wait) / 10;
return 0;
}
EXPORT_SYMBOL(usb_wwan_get_serial_info);
@@ -155,9 +155,10 @@ int usb_wwan_set_serial_info(struct tty_struct *tty,
unsigned int closing_wait, close_delay;
int retval = 0;
- close_delay = ss->close_delay * 10;
+ close_delay = msecs_to_jiffies(ss->close_delay * 10);
closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
- ASYNC_CLOSING_WAIT_NONE : ss->closing_wait * 10;
+ ASYNC_CLOSING_WAIT_NONE :
+ msecs_to_jiffies(ss->closing_wait * 10);
mutex_lock(&port->port.mutex);
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e359b4411c2836cf87c8776682d1b594635570de Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Fri, 16 Apr 2021 16:05:56 +0200
Subject: [PATCH] serial: stm32: fix threaded interrupt handling
When DMA is enabled the receive handler runs in a threaded handler, but
the primary handler up until very recently neither disabled interrupts
in the device or used IRQF_ONESHOT. This would lead to a deadlock if an
interrupt comes in while the threaded receive handler is running under
the port lock.
Commit ad7676812437 ("serial: stm32: fix a deadlock condition with
wakeup event") claimed to fix an unrelated deadlock, but unfortunately
also disabled interrupts in the threaded handler. While this prevents
the deadlock mentioned in the previous paragraph it also defeats the
purpose of using a threaded handler in the first place.
Fix this by making the interrupt one-shot and not disabling interrupts
in the threaded handler.
Note that (receive) DMA must not be used for a console port as the
threaded handler could be interrupted while holding the port lock,
something which could lead to a deadlock in case an interrupt handler
ends up calling printk.
Fixes: ad7676812437 ("serial: stm32: fix a deadlock condition with wakeup event")
Fixes: 3489187204eb ("serial: stm32: adding dma support")
Cc: stable(a)vger.kernel.org # 4.9
Cc: Alexandre TORGUE <alexandre.torgue(a)st.com>
Cc: Gerald Baeza <gerald.baeza(a)st.com>
Reviewed-by: Valentin Caron<valentin.caron(a)foss.st.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 4d277804c63e..3524ed2c0c73 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -214,14 +214,11 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
struct tty_port *tport = &port->state->port;
struct stm32_port *stm32_port = to_stm32_port(port);
const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
- unsigned long c, flags;
+ unsigned long c;
u32 sr;
char flag;
- if (threaded)
- spin_lock_irqsave(&port->lock, flags);
- else
- spin_lock(&port->lock);
+ spin_lock(&port->lock);
while (stm32_usart_pending_rx(port, &sr, &stm32_port->last_res,
threaded)) {
@@ -278,10 +275,7 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
uart_insert_char(port, sr, USART_SR_ORE, c, flag);
}
- if (threaded)
- spin_unlock_irqrestore(&port->lock, flags);
- else
- spin_unlock(&port->lock);
+ spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
}
@@ -667,7 +661,8 @@ static int stm32_usart_startup(struct uart_port *port)
ret = request_threaded_irq(port->irq, stm32_usart_interrupt,
stm32_usart_threaded_interrupt,
- IRQF_NO_SUSPEND, name, port);
+ IRQF_ONESHOT | IRQF_NO_SUSPEND,
+ name, port);
if (ret)
return ret;
@@ -1156,6 +1151,13 @@ static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port,
struct dma_async_tx_descriptor *desc = NULL;
int ret;
+ /*
+ * Using DMA and threaded handler for the console could lead to
+ * deadlocks.
+ */
+ if (uart_console(port))
+ return -ENODEV;
+
/* Request DMA RX channel */
stm32port->rx_ch = dma_request_slave_channel(dev, "rx");
if (!stm32port->rx_ch) {
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e359b4411c2836cf87c8776682d1b594635570de Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Fri, 16 Apr 2021 16:05:56 +0200
Subject: [PATCH] serial: stm32: fix threaded interrupt handling
When DMA is enabled the receive handler runs in a threaded handler, but
the primary handler up until very recently neither disabled interrupts
in the device or used IRQF_ONESHOT. This would lead to a deadlock if an
interrupt comes in while the threaded receive handler is running under
the port lock.
Commit ad7676812437 ("serial: stm32: fix a deadlock condition with
wakeup event") claimed to fix an unrelated deadlock, but unfortunately
also disabled interrupts in the threaded handler. While this prevents
the deadlock mentioned in the previous paragraph it also defeats the
purpose of using a threaded handler in the first place.
Fix this by making the interrupt one-shot and not disabling interrupts
in the threaded handler.
Note that (receive) DMA must not be used for a console port as the
threaded handler could be interrupted while holding the port lock,
something which could lead to a deadlock in case an interrupt handler
ends up calling printk.
Fixes: ad7676812437 ("serial: stm32: fix a deadlock condition with wakeup event")
Fixes: 3489187204eb ("serial: stm32: adding dma support")
Cc: stable(a)vger.kernel.org # 4.9
Cc: Alexandre TORGUE <alexandre.torgue(a)st.com>
Cc: Gerald Baeza <gerald.baeza(a)st.com>
Reviewed-by: Valentin Caron<valentin.caron(a)foss.st.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 4d277804c63e..3524ed2c0c73 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -214,14 +214,11 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
struct tty_port *tport = &port->state->port;
struct stm32_port *stm32_port = to_stm32_port(port);
const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
- unsigned long c, flags;
+ unsigned long c;
u32 sr;
char flag;
- if (threaded)
- spin_lock_irqsave(&port->lock, flags);
- else
- spin_lock(&port->lock);
+ spin_lock(&port->lock);
while (stm32_usart_pending_rx(port, &sr, &stm32_port->last_res,
threaded)) {
@@ -278,10 +275,7 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
uart_insert_char(port, sr, USART_SR_ORE, c, flag);
}
- if (threaded)
- spin_unlock_irqrestore(&port->lock, flags);
- else
- spin_unlock(&port->lock);
+ spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
}
@@ -667,7 +661,8 @@ static int stm32_usart_startup(struct uart_port *port)
ret = request_threaded_irq(port->irq, stm32_usart_interrupt,
stm32_usart_threaded_interrupt,
- IRQF_NO_SUSPEND, name, port);
+ IRQF_ONESHOT | IRQF_NO_SUSPEND,
+ name, port);
if (ret)
return ret;
@@ -1156,6 +1151,13 @@ static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port,
struct dma_async_tx_descriptor *desc = NULL;
int ret;
+ /*
+ * Using DMA and threaded handler for the console could lead to
+ * deadlocks.
+ */
+ if (uart_console(port))
+ return -ENODEV;
+
/* Request DMA RX channel */
stm32port->rx_ch = dma_request_slave_channel(dev, "rx");
if (!stm32port->rx_ch) {
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e359b4411c2836cf87c8776682d1b594635570de Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Fri, 16 Apr 2021 16:05:56 +0200
Subject: [PATCH] serial: stm32: fix threaded interrupt handling
When DMA is enabled the receive handler runs in a threaded handler, but
the primary handler up until very recently neither disabled interrupts
in the device or used IRQF_ONESHOT. This would lead to a deadlock if an
interrupt comes in while the threaded receive handler is running under
the port lock.
Commit ad7676812437 ("serial: stm32: fix a deadlock condition with
wakeup event") claimed to fix an unrelated deadlock, but unfortunately
also disabled interrupts in the threaded handler. While this prevents
the deadlock mentioned in the previous paragraph it also defeats the
purpose of using a threaded handler in the first place.
Fix this by making the interrupt one-shot and not disabling interrupts
in the threaded handler.
Note that (receive) DMA must not be used for a console port as the
threaded handler could be interrupted while holding the port lock,
something which could lead to a deadlock in case an interrupt handler
ends up calling printk.
Fixes: ad7676812437 ("serial: stm32: fix a deadlock condition with wakeup event")
Fixes: 3489187204eb ("serial: stm32: adding dma support")
Cc: stable(a)vger.kernel.org # 4.9
Cc: Alexandre TORGUE <alexandre.torgue(a)st.com>
Cc: Gerald Baeza <gerald.baeza(a)st.com>
Reviewed-by: Valentin Caron<valentin.caron(a)foss.st.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 4d277804c63e..3524ed2c0c73 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -214,14 +214,11 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
struct tty_port *tport = &port->state->port;
struct stm32_port *stm32_port = to_stm32_port(port);
const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
- unsigned long c, flags;
+ unsigned long c;
u32 sr;
char flag;
- if (threaded)
- spin_lock_irqsave(&port->lock, flags);
- else
- spin_lock(&port->lock);
+ spin_lock(&port->lock);
while (stm32_usart_pending_rx(port, &sr, &stm32_port->last_res,
threaded)) {
@@ -278,10 +275,7 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
uart_insert_char(port, sr, USART_SR_ORE, c, flag);
}
- if (threaded)
- spin_unlock_irqrestore(&port->lock, flags);
- else
- spin_unlock(&port->lock);
+ spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
}
@@ -667,7 +661,8 @@ static int stm32_usart_startup(struct uart_port *port)
ret = request_threaded_irq(port->irq, stm32_usart_interrupt,
stm32_usart_threaded_interrupt,
- IRQF_NO_SUSPEND, name, port);
+ IRQF_ONESHOT | IRQF_NO_SUSPEND,
+ name, port);
if (ret)
return ret;
@@ -1156,6 +1151,13 @@ static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port,
struct dma_async_tx_descriptor *desc = NULL;
int ret;
+ /*
+ * Using DMA and threaded handler for the console could lead to
+ * deadlocks.
+ */
+ if (uart_console(port))
+ return -ENODEV;
+
/* Request DMA RX channel */
stm32port->rx_ch = dma_request_slave_channel(dev, "rx");
if (!stm32port->rx_ch) {
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e359b4411c2836cf87c8776682d1b594635570de Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Fri, 16 Apr 2021 16:05:56 +0200
Subject: [PATCH] serial: stm32: fix threaded interrupt handling
When DMA is enabled the receive handler runs in a threaded handler, but
the primary handler up until very recently neither disabled interrupts
in the device or used IRQF_ONESHOT. This would lead to a deadlock if an
interrupt comes in while the threaded receive handler is running under
the port lock.
Commit ad7676812437 ("serial: stm32: fix a deadlock condition with
wakeup event") claimed to fix an unrelated deadlock, but unfortunately
also disabled interrupts in the threaded handler. While this prevents
the deadlock mentioned in the previous paragraph it also defeats the
purpose of using a threaded handler in the first place.
Fix this by making the interrupt one-shot and not disabling interrupts
in the threaded handler.
Note that (receive) DMA must not be used for a console port as the
threaded handler could be interrupted while holding the port lock,
something which could lead to a deadlock in case an interrupt handler
ends up calling printk.
Fixes: ad7676812437 ("serial: stm32: fix a deadlock condition with wakeup event")
Fixes: 3489187204eb ("serial: stm32: adding dma support")
Cc: stable(a)vger.kernel.org # 4.9
Cc: Alexandre TORGUE <alexandre.torgue(a)st.com>
Cc: Gerald Baeza <gerald.baeza(a)st.com>
Reviewed-by: Valentin Caron<valentin.caron(a)foss.st.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 4d277804c63e..3524ed2c0c73 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -214,14 +214,11 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
struct tty_port *tport = &port->state->port;
struct stm32_port *stm32_port = to_stm32_port(port);
const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
- unsigned long c, flags;
+ unsigned long c;
u32 sr;
char flag;
- if (threaded)
- spin_lock_irqsave(&port->lock, flags);
- else
- spin_lock(&port->lock);
+ spin_lock(&port->lock);
while (stm32_usart_pending_rx(port, &sr, &stm32_port->last_res,
threaded)) {
@@ -278,10 +275,7 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
uart_insert_char(port, sr, USART_SR_ORE, c, flag);
}
- if (threaded)
- spin_unlock_irqrestore(&port->lock, flags);
- else
- spin_unlock(&port->lock);
+ spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
}
@@ -667,7 +661,8 @@ static int stm32_usart_startup(struct uart_port *port)
ret = request_threaded_irq(port->irq, stm32_usart_interrupt,
stm32_usart_threaded_interrupt,
- IRQF_NO_SUSPEND, name, port);
+ IRQF_ONESHOT | IRQF_NO_SUSPEND,
+ name, port);
if (ret)
return ret;
@@ -1156,6 +1151,13 @@ static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port,
struct dma_async_tx_descriptor *desc = NULL;
int ret;
+ /*
+ * Using DMA and threaded handler for the console could lead to
+ * deadlocks.
+ */
+ if (uart_console(port))
+ return -ENODEV;
+
/* Request DMA RX channel */
stm32port->rx_ch = dma_request_slave_channel(dev, "rx");
if (!stm32port->rx_ch) {
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e359b4411c2836cf87c8776682d1b594635570de Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Fri, 16 Apr 2021 16:05:56 +0200
Subject: [PATCH] serial: stm32: fix threaded interrupt handling
When DMA is enabled the receive handler runs in a threaded handler, but
the primary handler up until very recently neither disabled interrupts
in the device or used IRQF_ONESHOT. This would lead to a deadlock if an
interrupt comes in while the threaded receive handler is running under
the port lock.
Commit ad7676812437 ("serial: stm32: fix a deadlock condition with
wakeup event") claimed to fix an unrelated deadlock, but unfortunately
also disabled interrupts in the threaded handler. While this prevents
the deadlock mentioned in the previous paragraph it also defeats the
purpose of using a threaded handler in the first place.
Fix this by making the interrupt one-shot and not disabling interrupts
in the threaded handler.
Note that (receive) DMA must not be used for a console port as the
threaded handler could be interrupted while holding the port lock,
something which could lead to a deadlock in case an interrupt handler
ends up calling printk.
Fixes: ad7676812437 ("serial: stm32: fix a deadlock condition with wakeup event")
Fixes: 3489187204eb ("serial: stm32: adding dma support")
Cc: stable(a)vger.kernel.org # 4.9
Cc: Alexandre TORGUE <alexandre.torgue(a)st.com>
Cc: Gerald Baeza <gerald.baeza(a)st.com>
Reviewed-by: Valentin Caron<valentin.caron(a)foss.st.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 4d277804c63e..3524ed2c0c73 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -214,14 +214,11 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
struct tty_port *tport = &port->state->port;
struct stm32_port *stm32_port = to_stm32_port(port);
const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
- unsigned long c, flags;
+ unsigned long c;
u32 sr;
char flag;
- if (threaded)
- spin_lock_irqsave(&port->lock, flags);
- else
- spin_lock(&port->lock);
+ spin_lock(&port->lock);
while (stm32_usart_pending_rx(port, &sr, &stm32_port->last_res,
threaded)) {
@@ -278,10 +275,7 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
uart_insert_char(port, sr, USART_SR_ORE, c, flag);
}
- if (threaded)
- spin_unlock_irqrestore(&port->lock, flags);
- else
- spin_unlock(&port->lock);
+ spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
}
@@ -667,7 +661,8 @@ static int stm32_usart_startup(struct uart_port *port)
ret = request_threaded_irq(port->irq, stm32_usart_interrupt,
stm32_usart_threaded_interrupt,
- IRQF_NO_SUSPEND, name, port);
+ IRQF_ONESHOT | IRQF_NO_SUSPEND,
+ name, port);
if (ret)
return ret;
@@ -1156,6 +1151,13 @@ static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port,
struct dma_async_tx_descriptor *desc = NULL;
int ret;
+ /*
+ * Using DMA and threaded handler for the console could lead to
+ * deadlocks.
+ */
+ if (uart_console(port))
+ return -ENODEV;
+
/* Request DMA RX channel */
stm32port->rx_ch = dma_request_slave_channel(dev, "rx");
if (!stm32port->rx_ch) {
The patch below does not apply to the 5.11-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e359b4411c2836cf87c8776682d1b594635570de Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Fri, 16 Apr 2021 16:05:56 +0200
Subject: [PATCH] serial: stm32: fix threaded interrupt handling
When DMA is enabled the receive handler runs in a threaded handler, but
the primary handler up until very recently neither disabled interrupts
in the device or used IRQF_ONESHOT. This would lead to a deadlock if an
interrupt comes in while the threaded receive handler is running under
the port lock.
Commit ad7676812437 ("serial: stm32: fix a deadlock condition with
wakeup event") claimed to fix an unrelated deadlock, but unfortunately
also disabled interrupts in the threaded handler. While this prevents
the deadlock mentioned in the previous paragraph it also defeats the
purpose of using a threaded handler in the first place.
Fix this by making the interrupt one-shot and not disabling interrupts
in the threaded handler.
Note that (receive) DMA must not be used for a console port as the
threaded handler could be interrupted while holding the port lock,
something which could lead to a deadlock in case an interrupt handler
ends up calling printk.
Fixes: ad7676812437 ("serial: stm32: fix a deadlock condition with wakeup event")
Fixes: 3489187204eb ("serial: stm32: adding dma support")
Cc: stable(a)vger.kernel.org # 4.9
Cc: Alexandre TORGUE <alexandre.torgue(a)st.com>
Cc: Gerald Baeza <gerald.baeza(a)st.com>
Reviewed-by: Valentin Caron<valentin.caron(a)foss.st.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 4d277804c63e..3524ed2c0c73 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -214,14 +214,11 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
struct tty_port *tport = &port->state->port;
struct stm32_port *stm32_port = to_stm32_port(port);
const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
- unsigned long c, flags;
+ unsigned long c;
u32 sr;
char flag;
- if (threaded)
- spin_lock_irqsave(&port->lock, flags);
- else
- spin_lock(&port->lock);
+ spin_lock(&port->lock);
while (stm32_usart_pending_rx(port, &sr, &stm32_port->last_res,
threaded)) {
@@ -278,10 +275,7 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
uart_insert_char(port, sr, USART_SR_ORE, c, flag);
}
- if (threaded)
- spin_unlock_irqrestore(&port->lock, flags);
- else
- spin_unlock(&port->lock);
+ spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
}
@@ -667,7 +661,8 @@ static int stm32_usart_startup(struct uart_port *port)
ret = request_threaded_irq(port->irq, stm32_usart_interrupt,
stm32_usart_threaded_interrupt,
- IRQF_NO_SUSPEND, name, port);
+ IRQF_ONESHOT | IRQF_NO_SUSPEND,
+ name, port);
if (ret)
return ret;
@@ -1156,6 +1151,13 @@ static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port,
struct dma_async_tx_descriptor *desc = NULL;
int ret;
+ /*
+ * Using DMA and threaded handler for the console could lead to
+ * deadlocks.
+ */
+ if (uart_console(port))
+ return -ENODEV;
+
/* Request DMA RX channel */
stm32port->rx_ch = dma_request_slave_channel(dev, "rx");
if (!stm32port->rx_ch) {
The patch below does not apply to the 5.12-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e359b4411c2836cf87c8776682d1b594635570de Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Fri, 16 Apr 2021 16:05:56 +0200
Subject: [PATCH] serial: stm32: fix threaded interrupt handling
When DMA is enabled the receive handler runs in a threaded handler, but
the primary handler up until very recently neither disabled interrupts
in the device or used IRQF_ONESHOT. This would lead to a deadlock if an
interrupt comes in while the threaded receive handler is running under
the port lock.
Commit ad7676812437 ("serial: stm32: fix a deadlock condition with
wakeup event") claimed to fix an unrelated deadlock, but unfortunately
also disabled interrupts in the threaded handler. While this prevents
the deadlock mentioned in the previous paragraph it also defeats the
purpose of using a threaded handler in the first place.
Fix this by making the interrupt one-shot and not disabling interrupts
in the threaded handler.
Note that (receive) DMA must not be used for a console port as the
threaded handler could be interrupted while holding the port lock,
something which could lead to a deadlock in case an interrupt handler
ends up calling printk.
Fixes: ad7676812437 ("serial: stm32: fix a deadlock condition with wakeup event")
Fixes: 3489187204eb ("serial: stm32: adding dma support")
Cc: stable(a)vger.kernel.org # 4.9
Cc: Alexandre TORGUE <alexandre.torgue(a)st.com>
Cc: Gerald Baeza <gerald.baeza(a)st.com>
Reviewed-by: Valentin Caron<valentin.caron(a)foss.st.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 4d277804c63e..3524ed2c0c73 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -214,14 +214,11 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
struct tty_port *tport = &port->state->port;
struct stm32_port *stm32_port = to_stm32_port(port);
const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
- unsigned long c, flags;
+ unsigned long c;
u32 sr;
char flag;
- if (threaded)
- spin_lock_irqsave(&port->lock, flags);
- else
- spin_lock(&port->lock);
+ spin_lock(&port->lock);
while (stm32_usart_pending_rx(port, &sr, &stm32_port->last_res,
threaded)) {
@@ -278,10 +275,7 @@ static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
uart_insert_char(port, sr, USART_SR_ORE, c, flag);
}
- if (threaded)
- spin_unlock_irqrestore(&port->lock, flags);
- else
- spin_unlock(&port->lock);
+ spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
}
@@ -667,7 +661,8 @@ static int stm32_usart_startup(struct uart_port *port)
ret = request_threaded_irq(port->irq, stm32_usart_interrupt,
stm32_usart_threaded_interrupt,
- IRQF_NO_SUSPEND, name, port);
+ IRQF_ONESHOT | IRQF_NO_SUSPEND,
+ name, port);
if (ret)
return ret;
@@ -1156,6 +1151,13 @@ static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port,
struct dma_async_tx_descriptor *desc = NULL;
int ret;
+ /*
+ * Using DMA and threaded handler for the console could lead to
+ * deadlocks.
+ */
+ if (uart_console(port))
+ return -ENODEV;
+
/* Request DMA RX channel */
stm32port->rx_ch = dma_request_slave_channel(dev, "rx");
if (!stm32port->rx_ch) {
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 729f7955cb987c5b7d7e54c87c5ad71c789934f7 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Thu, 8 Apr 2021 15:16:00 +0200
Subject: [PATCH] Revert "USB: cdc-acm: fix rounding error in TIOCSSERIAL"
This reverts commit b401f8c4f492cbf74f3f59c9141e5be3071071bb.
The offending commit claimed that trying to set the values reported back
by TIOCGSERIAL as a regular user could result in an -EPERM error when HZ
is 250, but that was never the case.
With HZ=250, the default 0.5 second value of close_delay is converted to
125 jiffies when set and is converted back to 50 centiseconds by
TIOCGSERIAL as expected (not 12 cs as was claimed, even if that was the
case before an earlier fix).
Comparing the internal current and new jiffies values is just fine to
determine if the value is about to change so drop the bogus workaround
(which was also backported to stable).
For completeness: With different default values for these parameters or
with a HZ value not divisible by two, the lack of rounding when setting
the default values in tty_port_init() could result in an -EPERM being
returned, but this is hardly something we need to worry about.
Cc: Anthony Mallet <anthony.mallet(a)laas.fr>
Cc: stable(a)vger.kernel.org
Acked-by: Oliver Neukum <oneukum(a)suse.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20210408131602.27956-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 3fda1ec961d7..96e221803fa6 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -942,7 +942,6 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
{
struct acm *acm = tty->driver_data;
unsigned int closing_wait, close_delay;
- unsigned int old_closing_wait, old_close_delay;
int retval = 0;
close_delay = msecs_to_jiffies(ss->close_delay * 10);
@@ -950,17 +949,11 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
ASYNC_CLOSING_WAIT_NONE :
msecs_to_jiffies(ss->closing_wait * 10);
- /* we must redo the rounding here, so that the values match */
- old_close_delay = jiffies_to_msecs(acm->port.close_delay) / 10;
- old_closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
- ASYNC_CLOSING_WAIT_NONE :
- jiffies_to_msecs(acm->port.closing_wait) / 10;
-
mutex_lock(&acm->port.mutex);
if (!capable(CAP_SYS_ADMIN)) {
- if ((ss->close_delay != old_close_delay) ||
- (ss->closing_wait != old_closing_wait))
+ if ((close_delay != acm->port.close_delay) ||
+ (closing_wait != acm->port.closing_wait))
retval = -EPERM;
else
retval = -EOPNOTSUPP;
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 729f7955cb987c5b7d7e54c87c5ad71c789934f7 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Thu, 8 Apr 2021 15:16:00 +0200
Subject: [PATCH] Revert "USB: cdc-acm: fix rounding error in TIOCSSERIAL"
This reverts commit b401f8c4f492cbf74f3f59c9141e5be3071071bb.
The offending commit claimed that trying to set the values reported back
by TIOCGSERIAL as a regular user could result in an -EPERM error when HZ
is 250, but that was never the case.
With HZ=250, the default 0.5 second value of close_delay is converted to
125 jiffies when set and is converted back to 50 centiseconds by
TIOCGSERIAL as expected (not 12 cs as was claimed, even if that was the
case before an earlier fix).
Comparing the internal current and new jiffies values is just fine to
determine if the value is about to change so drop the bogus workaround
(which was also backported to stable).
For completeness: With different default values for these parameters or
with a HZ value not divisible by two, the lack of rounding when setting
the default values in tty_port_init() could result in an -EPERM being
returned, but this is hardly something we need to worry about.
Cc: Anthony Mallet <anthony.mallet(a)laas.fr>
Cc: stable(a)vger.kernel.org
Acked-by: Oliver Neukum <oneukum(a)suse.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20210408131602.27956-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 3fda1ec961d7..96e221803fa6 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -942,7 +942,6 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
{
struct acm *acm = tty->driver_data;
unsigned int closing_wait, close_delay;
- unsigned int old_closing_wait, old_close_delay;
int retval = 0;
close_delay = msecs_to_jiffies(ss->close_delay * 10);
@@ -950,17 +949,11 @@ static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
ASYNC_CLOSING_WAIT_NONE :
msecs_to_jiffies(ss->closing_wait * 10);
- /* we must redo the rounding here, so that the values match */
- old_close_delay = jiffies_to_msecs(acm->port.close_delay) / 10;
- old_closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
- ASYNC_CLOSING_WAIT_NONE :
- jiffies_to_msecs(acm->port.closing_wait) / 10;
-
mutex_lock(&acm->port.mutex);
if (!capable(CAP_SYS_ADMIN)) {
- if ((ss->close_delay != old_close_delay) ||
- (ss->closing_wait != old_closing_wait))
+ if ((close_delay != acm->port.close_delay) ||
+ (closing_wait != acm->port.closing_wait))
retval = -EPERM;
else
retval = -EOPNOTSUPP;