diff options
Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0038-serial-milbeaut_usio-Use-port-lock-wrappers.patch | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/debian/patches-rt/0038-serial-milbeaut_usio-Use-port-lock-wrappers.patch b/debian/patches-rt/0038-serial-milbeaut_usio-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..47b1b7f3c --- /dev/null +++ b/debian/patches-rt/0038-serial-milbeaut_usio-Use-port-lock-wrappers.patch @@ -0,0 +1,101 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:55 +0206 +Subject: [PATCH 038/134] serial: milbeaut_usio: 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/20230914183831.587273-39-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/milbeaut_usio.c | 16 ++++++++-------- + 1 file changed, 8 insertions(+), 8 deletions(-) + +--- a/drivers/tty/serial/milbeaut_usio.c ++++ b/drivers/tty/serial/milbeaut_usio.c +@@ -207,9 +207,9 @@ static irqreturn_t mlb_usio_rx_irq(int i + { + struct uart_port *port = dev_id; + +- spin_lock(&port->lock); ++ uart_port_lock(port); + mlb_usio_rx_chars(port); +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + return IRQ_HANDLED; + } +@@ -218,10 +218,10 @@ static irqreturn_t mlb_usio_tx_irq(int i + { + struct uart_port *port = dev_id; + +- spin_lock(&port->lock); ++ uart_port_lock(port); + if (readb(port->membase + MLB_USIO_REG_SSR) & MLB_USIO_SSR_TBI) + mlb_usio_tx_chars(port); +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + return IRQ_HANDLED; + } +@@ -267,7 +267,7 @@ static int mlb_usio_startup(struct uart_ + escr = readb(port->membase + MLB_USIO_REG_ESCR); + if (of_property_read_bool(port->dev->of_node, "auto-flow-control")) + escr |= MLB_USIO_ESCR_FLWEN; +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + writeb(0, port->membase + MLB_USIO_REG_SCR); + writeb(escr, port->membase + MLB_USIO_REG_ESCR); + writeb(MLB_USIO_SCR_UPCL, port->membase + MLB_USIO_REG_SCR); +@@ -282,7 +282,7 @@ static int mlb_usio_startup(struct uart_ + + writeb(MLB_USIO_SCR_TXE | MLB_USIO_SCR_RIE | MLB_USIO_SCR_TBIE | + MLB_USIO_SCR_RXE, port->membase + MLB_USIO_REG_SCR); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + return 0; + } +@@ -337,7 +337,7 @@ static void mlb_usio_set_termios(struct + else + quot = 0; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + uart_update_timeout(port, termios->c_cflag, baud); + port->read_status_mask = MLB_USIO_SSR_ORE | MLB_USIO_SSR_RDRF | + MLB_USIO_SSR_TDRE; +@@ -367,7 +367,7 @@ static void mlb_usio_set_termios(struct + writew(BIT(12), port->membase + MLB_USIO_REG_FBYTE); + writeb(MLB_USIO_SCR_RIE | MLB_USIO_SCR_RXE | MLB_USIO_SCR_TBIE | + MLB_USIO_SCR_TXE, port->membase + MLB_USIO_REG_SCR); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static const char *mlb_usio_type(struct uart_port *port) |