This is a note to let you know that I've just added the patch titled
Revert "serial: core: Refactor uart_unlock_and_check_sysrq()"
to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 10652a9e9fe3fbcaca090f99cd3060ac3fee2913 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@xxxxxxxxxx>
Date: Wed, 10 Jun 2020 17:22:30 +0200
Subject: 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@xxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200610152232.16925-2-johan@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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 13fb92ae3710..fcdb6bfbe2cf 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 9fd550e7946a..ef4921ddbe97 100644
--- 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);
/*
--
2.27.0
