Revert "serial: core: Refactor uart_unlock_and_check_sysrq()"

This reverts commit da9a5aa3402db0ff3b57216d8dbf2478e1046cae.

In order to ease backporting a fix for a sysrq regression, revert this
rewrite which was since added on top.

The other sysrq helpers now 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.

Fixes: da9a5aa3402d ("serial: core: Refactor uart_unlock_and_check_sysrq()")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200610152232.16925-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 13fb92a..fcdb6bf 100644 (file)
--- 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 9fd550e..ef4921d 100644 (file)
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -464,7 +464,8 @@ 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);
 
 /*