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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/0013-serial-8250_pci1xxxx-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/0013-serial-8250_pci1xxxx-Use-port-lock-wrappers.patch | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/debian/patches-rt/0013-serial-8250_pci1xxxx-Use-port-lock-wrappers.patch b/debian/patches-rt/0013-serial-8250_pci1xxxx-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..2916387692 --- /dev/null +++ b/debian/patches-rt/0013-serial-8250_pci1xxxx-Use-port-lock-wrappers.patch @@ -0,0 +1,66 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:30 +0206 +Subject: [PATCH 013/134] serial: 8250_pci1xxxx: 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/20230914183831.587273-14-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/8250/8250_pci1xxxx.c | 8 ++++---- + 1 file changed, 4 insertions(+), 4 deletions(-) + +--- a/drivers/tty/serial/8250/8250_pci1xxxx.c ++++ b/drivers/tty/serial/8250/8250_pci1xxxx.c +@@ -225,10 +225,10 @@ static bool pci1xxxx_port_suspend(int li + if (port->suspended == 0 && port->dev) { + wakeup_mask = readb(up->port.membase + UART_WAKE_MASK_REG); + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + port->mctrl &= ~TIOCM_OUT2; + port->ops->set_mctrl(port, port->mctrl); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + ret = (wakeup_mask & UART_WAKE_SRCS) != UART_WAKE_SRCS; + } +@@ -251,10 +251,10 @@ static void pci1xxxx_port_resume(int lin + writeb(UART_WAKE_SRCS, port->membase + UART_WAKE_REG); + + if (port->suspended == 0) { +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + port->mctrl |= TIOCM_OUT2; + port->ops->set_mctrl(port, port->mctrl); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + mutex_unlock(&tport->mutex); + } |