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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:28:00 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:28:00 +0000 |
commit | 3565071f226432336a54d0193d729fa4508a3394 (patch) | |
tree | 4cde13f078f84c0a7785d234fd52edce7c90546a /debian/patches-rt/0073-serial-vt8500-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/0073-serial-vt8500-Use-port-lock-wrappers.patch | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/debian/patches-rt/0073-serial-vt8500-Use-port-lock-wrappers.patch b/debian/patches-rt/0073-serial-vt8500-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..7209ed0661 --- /dev/null +++ b/debian/patches-rt/0073-serial-vt8500-Use-port-lock-wrappers.patch @@ -0,0 +1,76 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:30 +0206 +Subject: [PATCH 073/134] serial: vt8500: 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/20230914183831.587273-74-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/vt8500_serial.c | 8 ++++---- + 1 file changed, 4 insertions(+), 4 deletions(-) + +--- a/drivers/tty/serial/vt8500_serial.c ++++ b/drivers/tty/serial/vt8500_serial.c +@@ -227,7 +227,7 @@ static irqreturn_t vt8500_irq(int irq, v + struct uart_port *port = dev_id; + unsigned long isr; + +- spin_lock(&port->lock); ++ uart_port_lock(port); + isr = vt8500_read(port, VT8500_URISR); + + /* Acknowledge active status bits */ +@@ -240,7 +240,7 @@ static irqreturn_t vt8500_irq(int irq, v + if (isr & TCTS) + handle_delta_cts(port); + +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + return IRQ_HANDLED; + } +@@ -342,7 +342,7 @@ static void vt8500_set_termios(struct ua + unsigned int baud, lcr; + unsigned int loops = 1000; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* calculate and set baud rate */ + baud = uart_get_baud_rate(port, termios, old, 900, 921600); +@@ -410,7 +410,7 @@ static void vt8500_set_termios(struct ua + vt8500_write(&vt8500_port->uart, 0x881, VT8500_URFCR); + vt8500_write(&vt8500_port->uart, vt8500_port->ier, VT8500_URIER); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static const char *vt8500_type(struct uart_port *port) |