diff options
Diffstat (limited to 'debian/patches-rt/0005-serial-8250_bcm7271-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0005-serial-8250_bcm7271-Use-port-lock-wrappers.patch | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/debian/patches-rt/0005-serial-8250_bcm7271-Use-port-lock-wrappers.patch b/debian/patches-rt/0005-serial-8250_bcm7271-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..55ae035b80 --- /dev/null +++ b/debian/patches-rt/0005-serial-8250_bcm7271-Use-port-lock-wrappers.patch @@ -0,0 +1,151 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:22 +0206 +Subject: [PATCH 005/134] serial: 8250_bcm7271: 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/20230914183831.587273-6-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/8250/8250_bcm7271.c | 28 ++++++++++++++-------------- + 1 file changed, 14 insertions(+), 14 deletions(-) + +--- a/drivers/tty/serial/8250/8250_bcm7271.c ++++ b/drivers/tty/serial/8250/8250_bcm7271.c +@@ -567,7 +567,7 @@ static irqreturn_t brcmuart_isr(int irq, + if (interrupts == 0) + return IRQ_NONE; + +- spin_lock_irqsave(&up->lock, flags); ++ uart_port_lock_irqsave(up, &flags); + + /* Clear all interrupts */ + udma_writel(priv, REGS_DMA_ISR, UDMA_INTR_CLEAR, interrupts); +@@ -581,7 +581,7 @@ static irqreturn_t brcmuart_isr(int irq, + if ((rval | tval) == 0) + dev_warn(dev, "Spurious interrupt: 0x%x\n", interrupts); + +- spin_unlock_irqrestore(&up->lock, flags); ++ uart_port_unlock_irqrestore(up, flags); + return IRQ_HANDLED; + } + +@@ -608,10 +608,10 @@ static int brcmuart_startup(struct uart_ + * + * Synchronize UART_IER access against the console. + */ +- spin_lock_irq(&port->lock); ++ uart_port_lock_irq(port); + up->ier &= ~UART_IER_RDI; + serial_port_out(port, UART_IER, up->ier); +- spin_unlock_irq(&port->lock); ++ uart_port_unlock_irq(port); + + priv->tx_running = false; + priv->dma.rx_dma = NULL; +@@ -629,7 +629,7 @@ static void brcmuart_shutdown(struct uar + struct brcmuart_priv *priv = up->port.private_data; + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + priv->shutdown = true; + if (priv->dma_enabled) { + stop_rx_dma(up); +@@ -645,7 +645,7 @@ static void brcmuart_shutdown(struct uar + */ + up->dma = NULL; + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + serial8250_do_shutdown(port); + } + +@@ -788,7 +788,7 @@ static int brcmuart_handle_irq(struct ua + * interrupt but there is no data ready. + */ + if (((iir & UART_IIR_ID) == UART_IIR_RX_TIMEOUT) && !(priv->shutdown)) { +- spin_lock_irqsave(&p->lock, flags); ++ uart_port_lock_irqsave(p, &flags); + status = serial_port_in(p, UART_LSR); + if ((status & UART_LSR_DR) == 0) { + +@@ -813,7 +813,7 @@ static int brcmuart_handle_irq(struct ua + + handled = 1; + } +- spin_unlock_irqrestore(&p->lock, flags); ++ uart_port_unlock_irqrestore(p, flags); + if (handled) + return 1; + } +@@ -831,7 +831,7 @@ static enum hrtimer_restart brcmuart_hrt + if (priv->shutdown) + return HRTIMER_NORESTART; + +- spin_lock_irqsave(&p->lock, flags); ++ uart_port_lock_irqsave(p, &flags); + status = serial_port_in(p, UART_LSR); + + /* +@@ -855,7 +855,7 @@ static enum hrtimer_restart brcmuart_hrt + status |= UART_MCR_RTS; + serial_port_out(p, UART_MCR, status); + } +- spin_unlock_irqrestore(&p->lock, flags); ++ uart_port_unlock_irqrestore(p, flags); + return HRTIMER_NORESTART; + } + +@@ -1154,10 +1154,10 @@ static int __maybe_unused brcmuart_suspe + * This will prevent resume from enabling RTS before the + * baud rate has been restored. + */ +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + priv->saved_mctrl = port->mctrl; + port->mctrl &= ~TIOCM_RTS; +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + serial8250_suspend_port(priv->line); + clk_disable_unprepare(priv->baud_mux_clk); +@@ -1196,10 +1196,10 @@ static int __maybe_unused brcmuart_resum + + if (priv->saved_mctrl & TIOCM_RTS) { + /* Restore RTS */ +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + port->mctrl |= TIOCM_RTS; + port->ops->set_mctrl(port, port->mctrl); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + return 0; |