diff options
Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0050-serial-rda-Use-port-lock-wrappers.patch | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/debian/patches-rt/0050-serial-rda-Use-port-lock-wrappers.patch b/debian/patches-rt/0050-serial-rda-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..6d51972bcd --- /dev/null +++ b/debian/patches-rt/0050-serial-rda-Use-port-lock-wrappers.patch @@ -0,0 +1,177 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:07 +0206 +Subject: [PATCH 050/134] serial: rda: 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/20230914183831.587273-51-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/rda-uart.c | 34 +++++++++++++++++----------------- + 1 file changed, 17 insertions(+), 17 deletions(-) + +--- a/drivers/tty/serial/rda-uart.c ++++ b/drivers/tty/serial/rda-uart.c +@@ -139,12 +139,12 @@ static unsigned int rda_uart_tx_empty(st + unsigned int ret; + u32 val; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + val = rda_uart_read(port, RDA_UART_STATUS); + ret = (val & RDA_UART_TX_FIFO_MASK) ? TIOCSER_TEMT : 0; + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + return ret; + } +@@ -246,7 +246,7 @@ static void rda_uart_set_termios(struct + unsigned int baud; + u32 irq_mask; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + baud = uart_get_baud_rate(port, termios, old, 9600, port->uartclk / 4); + rda_uart_change_baudrate(rda_port, baud); +@@ -325,7 +325,7 @@ static void rda_uart_set_termios(struct + /* update the per-port timeout */ + uart_update_timeout(port, termios->c_cflag, baud); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static void rda_uart_send_chars(struct uart_port *port) +@@ -408,7 +408,7 @@ static irqreturn_t rda_interrupt(int irq + unsigned long flags; + u32 val, irq_mask; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* Clear IRQ cause */ + val = rda_uart_read(port, RDA_UART_IRQ_CAUSE); +@@ -425,7 +425,7 @@ static irqreturn_t rda_interrupt(int irq + rda_uart_send_chars(port); + } + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + return IRQ_HANDLED; + } +@@ -436,16 +436,16 @@ static int rda_uart_startup(struct uart_ + int ret; + u32 val; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + rda_uart_write(port, 0, RDA_UART_IRQ_MASK); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + ret = request_irq(port->irq, rda_interrupt, IRQF_NO_SUSPEND, + "rda-uart", port); + if (ret) + return ret; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + val = rda_uart_read(port, RDA_UART_CTRL); + val |= RDA_UART_ENABLE; +@@ -456,7 +456,7 @@ static int rda_uart_startup(struct uart_ + val |= (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT); + rda_uart_write(port, val, RDA_UART_IRQ_MASK); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + return 0; + } +@@ -466,7 +466,7 @@ static void rda_uart_shutdown(struct uar + unsigned long flags; + u32 val; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + rda_uart_stop_tx(port); + rda_uart_stop_rx(port); +@@ -475,7 +475,7 @@ static void rda_uart_shutdown(struct uar + val &= ~RDA_UART_ENABLE; + rda_uart_write(port, val, RDA_UART_CTRL); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static const char *rda_uart_type(struct uart_port *port) +@@ -515,7 +515,7 @@ static void rda_uart_config_port(struct + rda_uart_request_port(port); + } + +- spin_lock_irqsave(&port->lock, irq_flags); ++ uart_port_lock_irqsave(port, &irq_flags); + + /* Clear mask, so no surprise interrupts. */ + rda_uart_write(port, 0, RDA_UART_IRQ_MASK); +@@ -523,7 +523,7 @@ static void rda_uart_config_port(struct + /* Clear status register */ + rda_uart_write(port, 0, RDA_UART_STATUS); + +- spin_unlock_irqrestore(&port->lock, irq_flags); ++ uart_port_unlock_irqrestore(port, irq_flags); + } + + static void rda_uart_release_port(struct uart_port *port) +@@ -597,9 +597,9 @@ static void rda_uart_port_write(struct u + if (port->sysrq) { + 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; + } + +@@ -615,7 +615,7 @@ static void rda_uart_port_write(struct u + rda_uart_write(port, old_irq_mask, RDA_UART_IRQ_MASK); + + if (locked) +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + local_irq_restore(flags); + } |