diff options
Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0066-serial-sunplus-uart-Use-port-lock-wrappers.patch | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/debian/patches-rt/0066-serial-sunplus-uart-Use-port-lock-wrappers.patch b/debian/patches-rt/0066-serial-sunplus-uart-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..10ae6c477 --- /dev/null +++ b/debian/patches-rt/0066-serial-sunplus-uart-Use-port-lock-wrappers.patch @@ -0,0 +1,146 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:23 +0206 +Subject: [PATCH 066/134] serial: sunplus-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/20230914183831.587273-67-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/sunplus-uart.c | 26 +++++++++++++------------- + 1 file changed, 13 insertions(+), 13 deletions(-) + +--- a/drivers/tty/serial/sunplus-uart.c ++++ b/drivers/tty/serial/sunplus-uart.c +@@ -184,7 +184,7 @@ static void sunplus_break_ctl(struct uar + unsigned long flags; + unsigned int lcr; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + lcr = readl(port->membase + SUP_UART_LCR); + +@@ -195,7 +195,7 @@ static void sunplus_break_ctl(struct uar + + writel(lcr, port->membase + SUP_UART_LCR); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static void transmit_chars(struct uart_port *port) +@@ -277,7 +277,7 @@ static irqreturn_t sunplus_uart_irq(int + struct uart_port *port = args; + unsigned int isc; + +- spin_lock(&port->lock); ++ uart_port_lock(port); + + isc = readl(port->membase + SUP_UART_ISC); + +@@ -287,7 +287,7 @@ static irqreturn_t sunplus_uart_irq(int + if (isc & SUP_UART_ISC_TX) + transmit_chars(port); + +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + return IRQ_HANDLED; + } +@@ -302,14 +302,14 @@ static int sunplus_startup(struct uart_p + if (ret) + return ret; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + /* isc define Bit[7:4] int setting, Bit[3:0] int status + * isc register will clean Bit[3:0] int status after read + * only do a write to Bit[7:4] int setting + */ + isc |= SUP_UART_ISC_RXM; + writel(isc, port->membase + SUP_UART_ISC); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + return 0; + } +@@ -318,13 +318,13 @@ static void sunplus_shutdown(struct uart + { + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + /* isc define Bit[7:4] int setting, Bit[3:0] int status + * isc register will clean Bit[3:0] int status after read + * only do a write to Bit[7:4] int setting + */ + writel(0, port->membase + SUP_UART_ISC); /* disable all interrupt */ +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + free_irq(port->irq, port); + } +@@ -372,7 +372,7 @@ static void sunplus_set_termios(struct u + lcr |= UART_LCR_EPAR; + } + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + uart_update_timeout(port, termios->c_cflag, baud); + +@@ -407,7 +407,7 @@ static void sunplus_set_termios(struct u + writel(div_l, port->membase + SUP_UART_DIV_L); + writel(lcr, port->membase + SUP_UART_LCR); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static void sunplus_set_ldisc(struct uart_port *port, struct ktermios *termios) +@@ -517,15 +517,15 @@ static void sunplus_console_write(struct + if (sunplus_console_ports[co->index]->port.sysrq) + locked = 0; + else if (oops_in_progress) +- locked = spin_trylock(&sunplus_console_ports[co->index]->port.lock); ++ locked = uart_port_trylock(&sunplus_console_ports[co->index]->port); + else +- spin_lock(&sunplus_console_ports[co->index]->port.lock); ++ uart_port_lock(&sunplus_console_ports[co->index]->port); + + uart_console_write(&sunplus_console_ports[co->index]->port, s, count, + sunplus_uart_console_putchar); + + if (locked) +- spin_unlock(&sunplus_console_ports[co->index]->port.lock); ++ uart_port_unlock(&sunplus_console_ports[co->index]->port); + + local_irq_restore(flags); + } |