diff options
Diffstat (limited to 'debian/patches-rt/0031-serial-jsm-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0031-serial-jsm-Use-port-lock-wrappers.patch | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/debian/patches-rt/0031-serial-jsm-Use-port-lock-wrappers.patch b/debian/patches-rt/0031-serial-jsm-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..4326b333a --- /dev/null +++ b/debian/patches-rt/0031-serial-jsm-Use-port-lock-wrappers.patch @@ -0,0 +1,124 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:48 +0206 +Subject: [PATCH 031/134] serial: jsm: 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/20230914183831.587273-32-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/jsm/jsm_neo.c | 4 ++-- + drivers/tty/serial/jsm/jsm_tty.c | 16 ++++++++-------- + 2 files changed, 10 insertions(+), 10 deletions(-) + +--- a/drivers/tty/serial/jsm/jsm_neo.c ++++ b/drivers/tty/serial/jsm/jsm_neo.c +@@ -816,9 +816,9 @@ static void neo_parse_isr(struct jsm_boa + /* Parse any modem signal changes */ + jsm_dbg(INTR, &ch->ch_bd->pci_dev, + "MOD_STAT: sending to parse_modem_sigs\n"); +- spin_lock_irqsave(&ch->uart_port.lock, lock_flags); ++ uart_port_lock_irqsave(&ch->uart_port, &lock_flags); + neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr)); +- spin_unlock_irqrestore(&ch->uart_port.lock, lock_flags); ++ uart_port_unlock_irqrestore(&ch->uart_port, lock_flags); + } + } + +--- a/drivers/tty/serial/jsm/jsm_tty.c ++++ b/drivers/tty/serial/jsm/jsm_tty.c +@@ -152,14 +152,14 @@ static void jsm_tty_send_xchar(struct ua + container_of(port, struct jsm_channel, uart_port); + struct ktermios *termios; + +- spin_lock_irqsave(&port->lock, lock_flags); ++ uart_port_lock_irqsave(port, &lock_flags); + termios = &port->state->port.tty->termios; + if (ch == termios->c_cc[VSTART]) + channel->ch_bd->bd_ops->send_start_character(channel); + + if (ch == termios->c_cc[VSTOP]) + channel->ch_bd->bd_ops->send_stop_character(channel); +- spin_unlock_irqrestore(&port->lock, lock_flags); ++ uart_port_unlock_irqrestore(port, lock_flags); + } + + static void jsm_tty_stop_rx(struct uart_port *port) +@@ -176,13 +176,13 @@ static void jsm_tty_break(struct uart_po + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + +- spin_lock_irqsave(&port->lock, lock_flags); ++ uart_port_lock_irqsave(port, &lock_flags); + if (break_state == -1) + channel->ch_bd->bd_ops->send_break(channel); + else + channel->ch_bd->bd_ops->clear_break(channel); + +- spin_unlock_irqrestore(&port->lock, lock_flags); ++ uart_port_unlock_irqrestore(port, lock_flags); + } + + static int jsm_tty_open(struct uart_port *port) +@@ -241,7 +241,7 @@ static int jsm_tty_open(struct uart_port + channel->ch_cached_lsr = 0; + channel->ch_stops_sent = 0; + +- spin_lock_irqsave(&port->lock, lock_flags); ++ uart_port_lock_irqsave(port, &lock_flags); + termios = &port->state->port.tty->termios; + channel->ch_c_cflag = termios->c_cflag; + channel->ch_c_iflag = termios->c_iflag; +@@ -261,7 +261,7 @@ static int jsm_tty_open(struct uart_port + jsm_carrier(channel); + + channel->ch_open_count++; +- spin_unlock_irqrestore(&port->lock, lock_flags); ++ uart_port_unlock_irqrestore(port, lock_flags); + + jsm_dbg(OPEN, &channel->ch_bd->pci_dev, "finish\n"); + return 0; +@@ -307,7 +307,7 @@ static void jsm_tty_set_termios(struct u + struct jsm_channel *channel = + container_of(port, struct jsm_channel, uart_port); + +- spin_lock_irqsave(&port->lock, lock_flags); ++ uart_port_lock_irqsave(port, &lock_flags); + channel->ch_c_cflag = termios->c_cflag; + channel->ch_c_iflag = termios->c_iflag; + channel->ch_c_oflag = termios->c_oflag; +@@ -317,7 +317,7 @@ static void jsm_tty_set_termios(struct u + + channel->ch_bd->bd_ops->param(channel); + jsm_carrier(channel); +- spin_unlock_irqrestore(&port->lock, lock_flags); ++ uart_port_unlock_irqrestore(port, lock_flags); + } + + static const char *jsm_tty_type(struct uart_port *port) |