diff options
Diffstat (limited to 'debian/patches-rt/0059-serial-txx9-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0059-serial-txx9-Use-port-lock-wrappers.patch | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/debian/patches-rt/0059-serial-txx9-Use-port-lock-wrappers.patch b/debian/patches-rt/0059-serial-txx9-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..bbe48684b --- /dev/null +++ b/debian/patches-rt/0059-serial-txx9-Use-port-lock-wrappers.patch @@ -0,0 +1,134 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:16 +0206 +Subject: [PATCH 059/134] serial: txx9: 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/20230914183831.587273-60-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/serial_txx9.c | 26 +++++++++++++------------- + 1 file changed, 13 insertions(+), 13 deletions(-) + +--- a/drivers/tty/serial/serial_txx9.c ++++ b/drivers/tty/serial/serial_txx9.c +@@ -335,13 +335,13 @@ static irqreturn_t serial_txx9_interrupt + unsigned int status; + + while (1) { +- spin_lock(&up->lock); ++ uart_port_lock(up); + status = sio_in(up, TXX9_SIDISR); + if (!(sio_in(up, TXX9_SIDICR) & TXX9_SIDICR_TIE)) + status &= ~TXX9_SIDISR_TDIS; + if (!(status & (TXX9_SIDISR_TDIS | TXX9_SIDISR_RDIS | + TXX9_SIDISR_TOUT))) { +- spin_unlock(&up->lock); ++ uart_port_unlock(up); + break; + } + +@@ -353,7 +353,7 @@ static irqreturn_t serial_txx9_interrupt + sio_mask(up, TXX9_SIDISR, + TXX9_SIDISR_TDIS | TXX9_SIDISR_RDIS | + TXX9_SIDISR_TOUT); +- spin_unlock(&up->lock); ++ uart_port_unlock(up); + + if (pass_counter++ > PASS_LIMIT) + break; +@@ -367,9 +367,9 @@ static unsigned int serial_txx9_tx_empty + unsigned long flags; + unsigned int ret; + +- spin_lock_irqsave(&up->lock, flags); ++ uart_port_lock_irqsave(up, &flags); + ret = (sio_in(up, TXX9_SICISR) & TXX9_SICISR_TXALS) ? TIOCSER_TEMT : 0; +- spin_unlock_irqrestore(&up->lock, flags); ++ uart_port_unlock_irqrestore(up, flags); + + return ret; + } +@@ -399,12 +399,12 @@ static void serial_txx9_break_ctl(struct + { + unsigned long flags; + +- spin_lock_irqsave(&up->lock, flags); ++ uart_port_lock_irqsave(up, &flags); + if (break_state == -1) + sio_set(up, TXX9_SIFLCR, TXX9_SIFLCR_TBRK); + else + sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_TBRK); +- spin_unlock_irqrestore(&up->lock, flags); ++ uart_port_unlock_irqrestore(up, flags); + } + + #if defined(CONFIG_SERIAL_TXX9_CONSOLE) || defined(CONFIG_CONSOLE_POLL) +@@ -517,9 +517,9 @@ static int serial_txx9_startup(struct ua + /* + * Now, initialize the UART + */ +- spin_lock_irqsave(&up->lock, flags); ++ uart_port_lock_irqsave(up, &flags); + serial_txx9_set_mctrl(up, up->mctrl); +- spin_unlock_irqrestore(&up->lock, flags); ++ uart_port_unlock_irqrestore(up, flags); + + /* Enable RX/TX */ + sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_RSDE | TXX9_SIFLCR_TSDE); +@@ -541,9 +541,9 @@ static void serial_txx9_shutdown(struct + */ + sio_out(up, TXX9_SIDICR, 0); /* disable all intrs */ + +- spin_lock_irqsave(&up->lock, flags); ++ uart_port_lock_irqsave(up, &flags); + serial_txx9_set_mctrl(up, up->mctrl); +- spin_unlock_irqrestore(&up->lock, flags); ++ uart_port_unlock_irqrestore(up, flags); + + /* + * Disable break condition +@@ -625,7 +625,7 @@ serial_txx9_set_termios(struct uart_port + * Ok, we're now changing the port state. Do it with + * interrupts disabled. + */ +- spin_lock_irqsave(&up->lock, flags); ++ uart_port_lock_irqsave(up, &flags); + + /* + * Update the per-port timeout. +@@ -676,7 +676,7 @@ serial_txx9_set_termios(struct uart_port + sio_out(up, TXX9_SIFCR, fcr); + + serial_txx9_set_mctrl(up, up->mctrl); +- spin_unlock_irqrestore(&up->lock, flags); ++ uart_port_unlock_irqrestore(up, flags); + } + + static void |