diff options
Diffstat (limited to 'debian/patches-rt/0051-serial-rp2-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0051-serial-rp2-Use-port-lock-wrappers.patch | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/debian/patches-rt/0051-serial-rp2-Use-port-lock-wrappers.patch b/debian/patches-rt/0051-serial-rp2-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..e2009ff4c --- /dev/null +++ b/debian/patches-rt/0051-serial-rp2-Use-port-lock-wrappers.patch @@ -0,0 +1,114 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:08 +0206 +Subject: [PATCH 051/134] serial: rp2: 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/20230914183831.587273-52-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/rp2.c | 20 ++++++++++---------- + 1 file changed, 10 insertions(+), 10 deletions(-) + +--- a/drivers/tty/serial/rp2.c ++++ b/drivers/tty/serial/rp2.c +@@ -276,9 +276,9 @@ static unsigned int rp2_uart_tx_empty(st + * But the TXEMPTY bit doesn't seem to work unless the TX IRQ is + * enabled. + */ +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + tx_fifo_bytes = readw(up->base + RP2_TX_FIFO_COUNT); +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + + return tx_fifo_bytes ? 0 : TIOCSER_TEMT; + } +@@ -323,10 +323,10 @@ static void rp2_uart_break_ctl(struct ua + { + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + rp2_rmw(port_to_up(port), RP2_TXRX_CTL, RP2_TXRX_CTL_BREAK_m, + break_state ? RP2_TXRX_CTL_BREAK_m : 0); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static void rp2_uart_enable_ms(struct uart_port *port) +@@ -383,7 +383,7 @@ static void rp2_uart_set_termios(struct + if (tty_termios_baud_rate(new)) + tty_termios_encode_baud_rate(new, baud, baud); + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* ignore all characters if CREAD is not set */ + port->ignore_status_mask = (new->c_cflag & CREAD) ? 0 : RP2_DUMMY_READ; +@@ -391,7 +391,7 @@ static void rp2_uart_set_termios(struct + __rp2_uart_set_termios(up, new->c_cflag, new->c_iflag, baud_div); + uart_update_timeout(port, new->c_cflag, baud); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static void rp2_rx_chars(struct rp2_uart_port *up) +@@ -440,7 +440,7 @@ static void rp2_ch_interrupt(struct rp2_ + { + u32 status; + +- spin_lock(&up->port.lock); ++ uart_port_lock(&up->port); + + /* + * The IRQ status bits are clear-on-write. Other status bits in +@@ -456,7 +456,7 @@ static void rp2_ch_interrupt(struct rp2_ + if (status & RP2_CHAN_STAT_MS_CHANGED_MASK) + wake_up_interruptible(&up->port.state->port.delta_msr_wait); + +- spin_unlock(&up->port.lock); ++ uart_port_unlock(&up->port); + } + + static int rp2_asic_interrupt(struct rp2_card *card, unsigned int asic_id) +@@ -516,10 +516,10 @@ static void rp2_uart_shutdown(struct uar + + rp2_uart_break_ctl(port, 0); + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + rp2_mask_ch_irq(up, up->idx, 0); + rp2_rmw(up, RP2_CHAN_STAT, 0, 0); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static const char *rp2_uart_type(struct uart_port *port) |