From a157270fbf37f822e1fa9e9faa8ed8c81da1eb28 Mon Sep 17 00:00:00 2001
From: "Ahmed S. Darwish" <a.darwish@linutronix.de>
Date: Mon, 8 Feb 2021 19:16:15 +0100
Subject: [PATCH] serial: core: Remove BUG_ON(in_interrupt()) check
The usage of in_interrupt() in drivers is phased out for various
reasons.
In both exported functions where BUG_ON(in_interrupt()) is invoked,
there is a mutex_lock() afterwards. mutex_lock() contains a
might_sleep() which will already trigger a stack trace if the target
functions is called from atomic context.
Remove the BUG_ON() and add a "Context: " in the kernel-doc instead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20210208181615.381861-3-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/tty/serial/serial_core.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 7dacdb6a853450..ba31e97d3d96b8 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2848,6 +2848,8 @@ static const struct attribute_group tty_dev_attr_group = {
* @drv: pointer to the uart low level driver structure for this port
* @uport: uart port structure to use for this port.
*
+ * Context: task context, might sleep
+ *
* This allows the driver to register its own uart_port structure
* with the core driver. The main purpose is to allow the low
* level uart drivers to expand uart_port, rather than having yet
@@ -2861,8 +2863,6 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
struct device *tty_dev;
int num_groups;
- BUG_ON(in_interrupt());
-
if (uport->line >= drv->nr)
return -EINVAL;
@@ -2951,6 +2951,8 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
* @drv: pointer to the uart low level driver structure for this port
* @uport: uart port structure for this port
*
+ * Context: task context, might sleep
+ *
* This unhooks (and hangs up) the specified port structure from the
* core driver. No further calls will be made to the low-level code
* for this port.
@@ -2963,8 +2965,6 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
struct tty_struct *tty;
int ret = 0;
- BUG_ON(in_interrupt());
-
mutex_lock(&port_mutex);
/*
--
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