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patch "Revert "serial: core: Refactor uart_unlock_and_check_sysrq()"" added to tty-linus

PATCH [email protected] 1 participant 1 message Jun 27, 2020

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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 <[email protected]>
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 <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
Reviewed-by Andy Shevchenko <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/tty/serial/serial_core.c | 23 +++++++++++++----------
 include/linux/serial_core.h      |  3 ++-
 2 files changed, 15 insertions(+), 11 deletions(-)
drivers/tty/serial/serial_core.c +13 -10
index 13fb92ae3710..fcdb6bfbe2cf 100644
@@ -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);
include/linux/serial_core.h +2 -1
index 9fd550e7946a..ef4921ddbe97 100644
@@ -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);
 
 /*
Signature · 1 line
2.27.0