diff options
Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0035-serial-mcf-Use-port-lock-wrappers.patch | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/debian/patches-rt/0035-serial-mcf-Use-port-lock-wrappers.patch b/debian/patches-rt/0035-serial-mcf-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..966618a3e --- /dev/null +++ b/debian/patches-rt/0035-serial-mcf-Use-port-lock-wrappers.patch @@ -0,0 +1,127 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:52 +0206 +Subject: [PATCH 035/134] serial: mcf: 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/20230914183831.587273-36-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/mcf.c | 20 ++++++++++---------- + 1 file changed, 10 insertions(+), 10 deletions(-) + +--- a/drivers/tty/serial/mcf.c ++++ b/drivers/tty/serial/mcf.c +@@ -135,12 +135,12 @@ static void mcf_break_ctl(struct uart_po + { + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + if (break_state == -1) + writeb(MCFUART_UCR_CMDBREAKSTART, port->membase + MCFUART_UCR); + else + writeb(MCFUART_UCR_CMDBREAKSTOP, port->membase + MCFUART_UCR); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + /****************************************************************************/ +@@ -150,7 +150,7 @@ static int mcf_startup(struct uart_port + struct mcf_uart *pp = container_of(port, struct mcf_uart, port); + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* Reset UART, get it into known state... */ + writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR); +@@ -164,7 +164,7 @@ static int mcf_startup(struct uart_port + pp->imr = MCFUART_UIR_RXREADY; + writeb(pp->imr, port->membase + MCFUART_UIMR); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + return 0; + } +@@ -176,7 +176,7 @@ static void mcf_shutdown(struct uart_por + struct mcf_uart *pp = container_of(port, struct mcf_uart, port); + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* Disable all interrupts now */ + pp->imr = 0; +@@ -186,7 +186,7 @@ static void mcf_shutdown(struct uart_por + writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR); + writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + /****************************************************************************/ +@@ -252,7 +252,7 @@ static void mcf_set_termios(struct uart_ + mr2 |= MCFUART_MR2_TXCTS; + } + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + if (port->rs485.flags & SER_RS485_ENABLED) { + dev_dbg(port->dev, "Setting UART to RS485\n"); + mr2 |= MCFUART_MR2_TXRTS; +@@ -273,7 +273,7 @@ static void mcf_set_termios(struct uart_ + port->membase + MCFUART_UCSR); + writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE, + port->membase + MCFUART_UCR); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + /****************************************************************************/ +@@ -350,7 +350,7 @@ static irqreturn_t mcf_interrupt(int irq + + isr = readb(port->membase + MCFUART_UISR) & pp->imr; + +- spin_lock(&port->lock); ++ uart_port_lock(port); + if (isr & MCFUART_UIR_RXREADY) { + mcf_rx_chars(pp); + ret = IRQ_HANDLED; +@@ -359,7 +359,7 @@ static irqreturn_t mcf_interrupt(int irq + mcf_tx_chars(pp); + ret = IRQ_HANDLED; + } +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + return ret; + } |