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Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0033-serial-lpc32xx_hs-Use-port-lock-wrappers.patch | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/debian/patches-rt/0033-serial-lpc32xx_hs-Use-port-lock-wrappers.patch b/debian/patches-rt/0033-serial-lpc32xx_hs-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..06518e846 --- /dev/null +++ b/debian/patches-rt/0033-serial-lpc32xx_hs-Use-port-lock-wrappers.patch @@ -0,0 +1,148 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:50 +0206 +Subject: [PATCH 033/134] serial: lpc32xx_hs: 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/20230914183831.587273-34-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/lpc32xx_hs.c | 26 +++++++++++++------------- + 1 file changed, 13 insertions(+), 13 deletions(-) + +--- a/drivers/tty/serial/lpc32xx_hs.c ++++ b/drivers/tty/serial/lpc32xx_hs.c +@@ -140,15 +140,15 @@ static void lpc32xx_hsuart_console_write + if (up->port.sysrq) + locked = 0; + else if (oops_in_progress) +- locked = spin_trylock(&up->port.lock); ++ locked = uart_port_trylock(&up->port); + else +- spin_lock(&up->port.lock); ++ uart_port_lock(&up->port); + + uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar); + wait_for_xmit_empty(&up->port); + + if (locked) +- spin_unlock(&up->port.lock); ++ uart_port_unlock(&up->port); + local_irq_restore(flags); + } + +@@ -298,7 +298,7 @@ static irqreturn_t serial_lpc32xx_interr + struct tty_port *tport = &port->state->port; + u32 status; + +- spin_lock(&port->lock); ++ uart_port_lock(port); + + /* Read UART status and clear latched interrupts */ + status = readl(LPC32XX_HSUART_IIR(port->membase)); +@@ -333,7 +333,7 @@ static irqreturn_t serial_lpc32xx_interr + __serial_lpc32xx_tx(port); + } + +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + return IRQ_HANDLED; + } +@@ -404,14 +404,14 @@ static void serial_lpc32xx_break_ctl(str + unsigned long flags; + u32 tmp; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + tmp = readl(LPC32XX_HSUART_CTRL(port->membase)); + if (break_state != 0) + tmp |= LPC32XX_HSU_BREAK; + else + tmp &= ~LPC32XX_HSU_BREAK; + writel(tmp, LPC32XX_HSUART_CTRL(port->membase)); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + /* port->lock is not held. */ +@@ -421,7 +421,7 @@ static int serial_lpc32xx_startup(struct + unsigned long flags; + u32 tmp; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + __serial_uart_flush(port); + +@@ -441,7 +441,7 @@ static int serial_lpc32xx_startup(struct + + lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */ + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + retval = request_irq(port->irq, serial_lpc32xx_interrupt, + 0, MODNAME, port); +@@ -458,7 +458,7 @@ static void serial_lpc32xx_shutdown(stru + u32 tmp; + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B | + LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B; +@@ -466,7 +466,7 @@ static void serial_lpc32xx_shutdown(stru + + lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */ + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + free_irq(port->irq, port); + } +@@ -491,7 +491,7 @@ static void serial_lpc32xx_set_termios(s + + quot = __serial_get_clock_div(port->uartclk, baud); + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* Ignore characters? */ + tmp = readl(LPC32XX_HSUART_CTRL(port->membase)); +@@ -505,7 +505,7 @@ static void serial_lpc32xx_set_termios(s + + uart_update_timeout(port, termios->c_cflag, baud); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + /* Don't rewrite B0 */ + if (tty_termios_baud_rate(termios)) |