diff options
Diffstat (limited to 'debian/patches-rt/0026-serial-linflexuart-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0026-serial-linflexuart-Use-port-lock-wrappers.patch | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/debian/patches-rt/0026-serial-linflexuart-Use-port-lock-wrappers.patch b/debian/patches-rt/0026-serial-linflexuart-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..e2a3628ae5 --- /dev/null +++ b/debian/patches-rt/0026-serial-linflexuart-Use-port-lock-wrappers.patch @@ -0,0 +1,143 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:43 +0206 +Subject: [PATCH 026/134] serial: linflexuart: 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/20230914183831.587273-27-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/fsl_linflexuart.c | 26 +++++++++++++------------- + 1 file changed, 13 insertions(+), 13 deletions(-) + +--- a/drivers/tty/serial/fsl_linflexuart.c ++++ b/drivers/tty/serial/fsl_linflexuart.c +@@ -203,7 +203,7 @@ static irqreturn_t linflex_txint(int irq + struct circ_buf *xmit = &sport->state->xmit; + unsigned long flags; + +- spin_lock_irqsave(&sport->lock, flags); ++ uart_port_lock_irqsave(sport, &flags); + + if (sport->x_char) { + linflex_put_char(sport, sport->x_char); +@@ -217,7 +217,7 @@ static irqreturn_t linflex_txint(int irq + + linflex_transmit_buffer(sport); + out: +- spin_unlock_irqrestore(&sport->lock, flags); ++ uart_port_unlock_irqrestore(sport, flags); + return IRQ_HANDLED; + } + +@@ -230,7 +230,7 @@ static irqreturn_t linflex_rxint(int irq + unsigned char rx; + bool brk; + +- spin_lock_irqsave(&sport->lock, flags); ++ uart_port_lock_irqsave(sport, &flags); + + status = readl(sport->membase + UARTSR); + while (status & LINFLEXD_UARTSR_RMB) { +@@ -266,7 +266,7 @@ static irqreturn_t linflex_rxint(int irq + } + } + +- spin_unlock_irqrestore(&sport->lock, flags); ++ uart_port_unlock_irqrestore(sport, flags); + + tty_flip_buffer_push(port); + +@@ -369,11 +369,11 @@ static int linflex_startup(struct uart_p + int ret = 0; + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + linflex_setup_watermark(port); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + ret = devm_request_irq(port->dev, port->irq, linflex_int, 0, + DRIVER_NAME, port); +@@ -386,14 +386,14 @@ static void linflex_shutdown(struct uart + unsigned long ier; + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* disable interrupts */ + ier = readl(port->membase + LINIER); + ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE); + writel(ier, port->membase + LINIER); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + devm_free_irq(port->dev, port->irq, port); + } +@@ -474,7 +474,7 @@ linflex_set_termios(struct uart_port *po + cr &= ~LINFLEXD_UARTCR_PCE; + } + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + port->read_status_mask = 0; + +@@ -507,7 +507,7 @@ linflex_set_termios(struct uart_port *po + + writel(cr1, port->membase + LINCR1); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static const char *linflex_type(struct uart_port *port) +@@ -646,14 +646,14 @@ linflex_console_write(struct console *co + if (sport->sysrq) + locked = 0; + else if (oops_in_progress) +- locked = spin_trylock_irqsave(&sport->lock, flags); ++ locked = uart_port_trylock_irqsave(sport, &flags); + else +- spin_lock_irqsave(&sport->lock, flags); ++ uart_port_lock_irqsave(sport, &flags); + + linflex_string_write(sport, s, count); + + if (locked) +- spin_unlock_irqrestore(&sport->lock, flags); ++ uart_port_unlock_irqrestore(sport, flags); + } + + /* |