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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/0040-serial-mps2-uart-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 'debian/patches-rt/0040-serial-mps2-uart-Use-port-lock-wrappers.patch')
-rw-r--r-- | debian/patches-rt/0040-serial-mps2-uart-Use-port-lock-wrappers.patch | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/debian/patches-rt/0040-serial-mps2-uart-Use-port-lock-wrappers.patch b/debian/patches-rt/0040-serial-mps2-uart-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..a626bdb031 --- /dev/null +++ b/debian/patches-rt/0040-serial-mps2-uart-Use-port-lock-wrappers.patch @@ -0,0 +1,103 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:57 +0206 +Subject: [PATCH 040/134] serial: mps2-uart: 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/20230914183831.587273-41-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/mps2-uart.c | 16 ++++++++-------- + 1 file changed, 8 insertions(+), 8 deletions(-) + +--- a/drivers/tty/serial/mps2-uart.c ++++ b/drivers/tty/serial/mps2-uart.c +@@ -188,12 +188,12 @@ static irqreturn_t mps2_uart_rxirq(int i + if (unlikely(!(irqflag & UARTn_INT_RX))) + return IRQ_NONE; + +- spin_lock(&port->lock); ++ uart_port_lock(port); + + mps2_uart_write8(port, UARTn_INT_RX, UARTn_INT); + mps2_uart_rx_chars(port); + +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + return IRQ_HANDLED; + } +@@ -206,12 +206,12 @@ static irqreturn_t mps2_uart_txirq(int i + if (unlikely(!(irqflag & UARTn_INT_TX))) + return IRQ_NONE; + +- spin_lock(&port->lock); ++ uart_port_lock(port); + + mps2_uart_write8(port, UARTn_INT_TX, UARTn_INT); + mps2_uart_tx_chars(port); + +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + return IRQ_HANDLED; + } +@@ -222,7 +222,7 @@ static irqreturn_t mps2_uart_oerrirq(int + struct uart_port *port = data; + u8 irqflag = mps2_uart_read8(port, UARTn_INT); + +- spin_lock(&port->lock); ++ uart_port_lock(port); + + if (irqflag & UARTn_INT_RX_OVERRUN) { + struct tty_port *tport = &port->state->port; +@@ -244,7 +244,7 @@ static irqreturn_t mps2_uart_oerrirq(int + handled = IRQ_HANDLED; + } + +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + return handled; + } +@@ -356,12 +356,12 @@ mps2_uart_set_termios(struct uart_port * + + bauddiv = DIV_ROUND_CLOSEST(port->uartclk, baud); + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + uart_update_timeout(port, termios->c_cflag, baud); + mps2_uart_write32(port, bauddiv, UARTn_BAUDDIV); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + if (tty_termios_baud_rate(termios)) + tty_termios_encode_baud_rate(termios, baud, baud); |