[PATCH 1/4] Revert "serial: core: Refactor uart_unlock_and_check_sysrq()"

From: Johan Hovold
Date: Tue Jun 02 2020 - 10:01:36 EST


This reverts commit da9a5aa3402db0ff3b57216d8dbf2478e1046cae.

In order to ease backporting a fix for broken port unlock, revert this
rewrite which was since added on top.

The other sysrq helpers bail out early when sysrq is not enabled; it's
better to keep that pattern here as well.

Note that the __releases() attribute won't be needed after the follow-on
fix either.

Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/tty/serial/serial_core.c | 23 +++++++++++++----------
include/linux/serial_core.h | 3 ++-
2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 66a5e2faf57e..edfb7bc14bbf 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -3239,19 +3239,22 @@ int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
}
EXPORT_SYMBOL_GPL(uart_prepare_sysrq_char);

-void uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long flags)
-__releases(&port->lock)
+void uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
{
- if (port->has_sysrq) {
- int sysrq_ch = port->sysrq_ch;
+ int sysrq_ch;

- port->sysrq_ch = 0;
- spin_unlock_irqrestore(&port->lock, flags);
- if (sysrq_ch)
- handle_sysrq(sysrq_ch);
- } else {
- spin_unlock_irqrestore(&port->lock, flags);
+ if (!port->has_sysrq) {
+ spin_unlock_irqrestore(&port->lock, irqflags);
+ return;
}
+
+ sysrq_ch = port->sysrq_ch;
+ port->sysrq_ch = 0;
+
+ spin_unlock_irqrestore(&port->lock, irqflags);
+
+ if (sysrq_ch)
+ handle_sysrq(sysrq_ch);
}
EXPORT_SYMBOL_GPL(uart_unlock_and_check_sysrq);

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 92f5eba86052..1f4443db5474 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -462,7 +462,8 @@ extern void uart_insert_char(struct uart_port *port, unsigned int status,

extern int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch);
extern int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch);
-extern void uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long flags);
+extern void uart_unlock_and_check_sysrq(struct uart_port *port,
+ unsigned long irqflags);
extern int uart_handle_break(struct uart_port *port);

/*
--
2.26.2