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Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0015-serial-altera_uart-Use-port-lock-wrappers.patch | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/debian/patches-rt/0015-serial-altera_uart-Use-port-lock-wrappers.patch b/debian/patches-rt/0015-serial-altera_uart-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..95e2c031f5 --- /dev/null +++ b/debian/patches-rt/0015-serial-altera_uart-Use-port-lock-wrappers.patch @@ -0,0 +1,116 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:32 +0206 +Subject: [PATCH 015/134] serial: altera_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/20230914183831.587273-16-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/altera_uart.c | 20 ++++++++++---------- + 1 file changed, 10 insertions(+), 10 deletions(-) + +--- a/drivers/tty/serial/altera_uart.c ++++ b/drivers/tty/serial/altera_uart.c +@@ -164,13 +164,13 @@ static void altera_uart_break_ctl(struct + struct altera_uart *pp = container_of(port, struct altera_uart, port); + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + if (break_state == -1) + pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK; + else + pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK; + altera_uart_update_ctrl_reg(pp); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static void altera_uart_set_termios(struct uart_port *port, +@@ -187,10 +187,10 @@ static void altera_uart_set_termios(stru + tty_termios_copy_hw(termios, old); + tty_termios_encode_baud_rate(termios, baud, baud); + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + uart_update_timeout(port, termios->c_cflag, baud); + altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + /* + * FIXME: port->read_status_mask and port->ignore_status_mask +@@ -264,12 +264,12 @@ static irqreturn_t altera_uart_interrupt + + isr = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + if (isr & ALTERA_UART_STATUS_RRDY_MSK) + altera_uart_rx_chars(port); + if (isr & ALTERA_UART_STATUS_TRDY_MSK) + altera_uart_tx_chars(port); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + return IRQ_RETVAL(isr); + } +@@ -313,13 +313,13 @@ static int altera_uart_startup(struct ua + } + } + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* Enable RX interrupts now */ + pp->imr = ALTERA_UART_CONTROL_RRDY_MSK; + altera_uart_update_ctrl_reg(pp); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + return 0; + } +@@ -329,13 +329,13 @@ static void altera_uart_shutdown(struct + struct altera_uart *pp = container_of(port, struct altera_uart, port); + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* Disable all interrupts now */ + pp->imr = 0; + altera_uart_update_ctrl_reg(pp); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + if (port->irq) + free_irq(port->irq, port); |