diff options
Diffstat (limited to 'debian/patches-rt/0022-serial-bcm63xx-uart-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0022-serial-bcm63xx-uart-Use-port-lock-wrappers.patch | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/debian/patches-rt/0022-serial-bcm63xx-uart-Use-port-lock-wrappers.patch b/debian/patches-rt/0022-serial-bcm63xx-uart-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..90efec4080 --- /dev/null +++ b/debian/patches-rt/0022-serial-bcm63xx-uart-Use-port-lock-wrappers.patch @@ -0,0 +1,128 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:39 +0206 +Subject: [PATCH 022/134] serial: bcm63xx-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> +Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> +Signed-off-by: John Ogness <john.ogness@linutronix.de> +Link: https://lore.kernel.org/r/20230914183831.587273-23-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/bcm63xx_uart.c | 22 +++++++++++----------- + 1 file changed, 11 insertions(+), 11 deletions(-) + +--- a/drivers/tty/serial/bcm63xx_uart.c ++++ b/drivers/tty/serial/bcm63xx_uart.c +@@ -201,7 +201,7 @@ static void bcm_uart_break_ctl(struct ua + unsigned long flags; + unsigned int val; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + val = bcm_uart_readl(port, UART_CTL_REG); + if (ctl) +@@ -210,7 +210,7 @@ static void bcm_uart_break_ctl(struct ua + val &= ~UART_CTL_XMITBRK_MASK; + bcm_uart_writel(port, val, UART_CTL_REG); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + /* +@@ -332,7 +332,7 @@ static irqreturn_t bcm_uart_interrupt(in + unsigned int irqstat; + + port = dev_id; +- spin_lock(&port->lock); ++ uart_port_lock(port); + + irqstat = bcm_uart_readl(port, UART_IR_REG); + if (irqstat & UART_RX_INT_STAT) +@@ -353,7 +353,7 @@ static irqreturn_t bcm_uart_interrupt(in + estat & UART_EXTINP_DCD_MASK); + } + +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + return IRQ_HANDLED; + } + +@@ -451,9 +451,9 @@ static void bcm_uart_shutdown(struct uar + { + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + bcm_uart_writel(port, 0, UART_IR_REG); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + bcm_uart_disable(port); + bcm_uart_flush(port); +@@ -470,7 +470,7 @@ static void bcm_uart_set_termios(struct + unsigned long flags; + int tries; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* Drain the hot tub fully before we power it off for the winter. */ + for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--) +@@ -546,7 +546,7 @@ static void bcm_uart_set_termios(struct + + uart_update_timeout(port, new->c_cflag, baud); + bcm_uart_enable(port); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + /* +@@ -712,9 +712,9 @@ static void bcm_console_write(struct con + /* bcm_uart_interrupt() already took the lock */ + locked = 0; + } else if (oops_in_progress) { +- locked = spin_trylock(&port->lock); ++ locked = uart_port_trylock(port); + } else { +- spin_lock(&port->lock); ++ uart_port_lock(port); + locked = 1; + } + +@@ -725,7 +725,7 @@ static void bcm_console_write(struct con + wait_for_xmitr(port); + + if (locked) +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + local_irq_restore(flags); + } + |