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@kernel.org 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@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 --- 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);

/*