diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:28:00 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:28:00 +0000 |
commit | 3565071f226432336a54d0193d729fa4508a3394 (patch) | |
tree | 4cde13f078f84c0a7785d234fd52edce7c90546a /debian/patches-rt/0018-serial-apb-Use-port-lock-wrappers.patch | |
parent | Adding upstream version 6.6.15. (diff) | |
download | linux-3565071f226432336a54d0193d729fa4508a3394.tar.xz linux-3565071f226432336a54d0193d729fa4508a3394.zip |
Adding debian version 6.6.15-2.debian/6.6.15-2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | debian/patches-rt/0018-serial-apb-Use-port-lock-wrappers.patch | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/debian/patches-rt/0018-serial-apb-Use-port-lock-wrappers.patch b/debian/patches-rt/0018-serial-apb-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..4dcf54a895 --- /dev/null +++ b/debian/patches-rt/0018-serial-apb-Use-port-lock-wrappers.patch @@ -0,0 +1,76 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:35 +0206 +Subject: [PATCH 018/134] serial: apb: Use port lock wrappers +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz + +When a serial port is used for kernel console output, then all +modifications to the UART registers which are done from other contexts, +e.g. getty, termios, are interference points for the kernel console. + +So far this has been ignored and the printk output is based on the +principle of hope. The rework of the console infrastructure which aims to +support threaded and atomic consoles, requires to mark sections which +modify the UART registers as unsafe. This allows the atomic write function +to make informed decisions and eventually to restore operational state. It +also allows to prevent the regular UART code from modifying UART registers +while printk output is in progress. + +All modifications of UART registers are guarded by the UART port lock, +which provides an obvious synchronization point with the console +infrastructure. + +To avoid adding this functionality to all UART drivers, wrap the +spin_[un]lock*() invocations for uart_port::lock into helper functions +which just contain the spin_[un]lock*() invocations for now. In a +subsequent step these helpers will gain the console synchronization +mechanisms. + +Converted with coccinelle. No functional change. + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Signed-off-by: John Ogness <john.ogness@linutronix.de> +Link: https://lore.kernel.org/r/20230914183831.587273-19-john.ogness@linutronix.de +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/tty/serial/apbuart.c | 8 ++++---- + 1 file changed, 4 insertions(+), 4 deletions(-) + +--- a/drivers/tty/serial/apbuart.c ++++ b/drivers/tty/serial/apbuart.c +@@ -133,7 +133,7 @@ static irqreturn_t apbuart_int(int irq, + struct uart_port *port = dev_id; + unsigned int status; + +- spin_lock(&port->lock); ++ uart_port_lock(port); + + status = UART_GET_STATUS(port); + if (status & UART_STATUS_DR) +@@ -141,7 +141,7 @@ static irqreturn_t apbuart_int(int irq, + if (status & UART_STATUS_THE) + apbuart_tx_chars(port); + +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + return IRQ_HANDLED; + } +@@ -228,7 +228,7 @@ static void apbuart_set_termios(struct u + if (termios->c_cflag & CRTSCTS) + cr |= UART_CTRL_FL; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* Update the per-port timeout. */ + uart_update_timeout(port, termios->c_cflag, baud); +@@ -251,7 +251,7 @@ static void apbuart_set_termios(struct u + UART_PUT_SCAL(port, quot); + UART_PUT_CTRL(port, cr); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static const char *apbuart_type(struct uart_port *port) |