diff options
Diffstat (limited to 'debian/patches-rt/0043-serial-omap-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0043-serial-omap-Use-port-lock-wrappers.patch | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/debian/patches-rt/0043-serial-omap-Use-port-lock-wrappers.patch b/debian/patches-rt/0043-serial-omap-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..a79d6253c4 --- /dev/null +++ b/debian/patches-rt/0043-serial-omap-Use-port-lock-wrappers.patch @@ -0,0 +1,180 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:00 +0206 +Subject: [PATCH 043/134] serial: omap: 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/20230914183831.587273-44-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/omap-serial.c | 38 +++++++++++++++++++------------------- + 1 file changed, 19 insertions(+), 19 deletions(-) + +--- a/drivers/tty/serial/omap-serial.c ++++ b/drivers/tty/serial/omap-serial.c +@@ -390,10 +390,10 @@ static void serial_omap_throttle(struct + struct uart_omap_port *up = to_uart_omap_port(port); + unsigned long flags; + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); + serial_out(up, UART_IER, up->ier); +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + } + + static void serial_omap_unthrottle(struct uart_port *port) +@@ -401,10 +401,10 @@ static void serial_omap_unthrottle(struc + struct uart_omap_port *up = to_uart_omap_port(port); + unsigned long flags; + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + up->ier |= UART_IER_RLSI | UART_IER_RDI; + serial_out(up, UART_IER, up->ier); +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + } + + static unsigned int check_modem_status(struct uart_omap_port *up) +@@ -527,7 +527,7 @@ static irqreturn_t serial_omap_irq(int i + irqreturn_t ret = IRQ_NONE; + int max_count = 256; + +- spin_lock(&up->port.lock); ++ uart_port_lock(&up->port); + + do { + iir = serial_in(up, UART_IIR); +@@ -563,7 +563,7 @@ static irqreturn_t serial_omap_irq(int i + } + } while (max_count--); + +- spin_unlock(&up->port.lock); ++ uart_port_unlock(&up->port); + + tty_flip_buffer_push(&up->port.state->port); + +@@ -579,9 +579,9 @@ static unsigned int serial_omap_tx_empty + unsigned int ret = 0; + + dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->port.line); +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0; +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + + return ret; + } +@@ -647,13 +647,13 @@ static void serial_omap_break_ctl(struct + unsigned long flags; + + dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->port.line); +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + if (break_state == -1) + up->lcr |= UART_LCR_SBC; + else + up->lcr &= ~UART_LCR_SBC; + serial_out(up, UART_LCR, up->lcr); +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + } + + static int serial_omap_startup(struct uart_port *port) +@@ -701,13 +701,13 @@ static int serial_omap_startup(struct ua + * Now, initialize the UART + */ + serial_out(up, UART_LCR, UART_LCR_WLEN8); +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + /* + * Most PC uarts need OUT2 raised to enable interrupts. + */ + up->port.mctrl |= TIOCM_OUT2; + serial_omap_set_mctrl(&up->port, up->port.mctrl); +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + + up->msr_saved_flags = 0; + /* +@@ -742,10 +742,10 @@ static void serial_omap_shutdown(struct + up->ier = 0; + serial_out(up, UART_IER, 0); + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + up->port.mctrl &= ~TIOCM_OUT2; + serial_omap_set_mctrl(&up->port, up->port.mctrl); +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + + /* + * Disable break condition and FIFOs +@@ -815,7 +815,7 @@ serial_omap_set_termios(struct uart_port + * Ok, we're now changing the port state. Do it with + * interrupts disabled. + */ +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + /* + * Update the per-port timeout. +@@ -1013,7 +1013,7 @@ serial_omap_set_termios(struct uart_port + + serial_omap_set_mctrl(&up->port, up->port.mctrl); + +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->port.line); + } + +@@ -1216,9 +1216,9 @@ serial_omap_console_write(struct console + 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); + + /* + * First save the IER then disable the interrupts +@@ -1245,7 +1245,7 @@ serial_omap_console_write(struct console + check_modem_status(up); + + if (locked) +- spin_unlock(&up->port.lock); ++ uart_port_unlock(&up->port); + local_irq_restore(flags); + } + |