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-rw-r--r--debian/patches-rt/0012-serial-8250_omap-Use-port-lock-wrappers.patch236
1 files changed, 236 insertions, 0 deletions
diff --git a/debian/patches-rt/0012-serial-8250_omap-Use-port-lock-wrappers.patch b/debian/patches-rt/0012-serial-8250_omap-Use-port-lock-wrappers.patch
new file mode 100644
index 000000000..10ebd70ea
--- /dev/null
+++ b/debian/patches-rt/0012-serial-8250_omap-Use-port-lock-wrappers.patch
@@ -0,0 +1,236 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:43:29 +0206
+Subject: [PATCH 012/134] serial: 8250_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/20230914183831.587273-13-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_omap.c | 52 ++++++++++++++++++------------------
+ 1 file changed, 26 insertions(+), 26 deletions(-)
+
+--- a/drivers/tty/serial/8250/8250_omap.c
++++ b/drivers/tty/serial/8250/8250_omap.c
+@@ -401,7 +401,7 @@ static void omap_8250_set_termios(struct
+ * interrupts disabled.
+ */
+ pm_runtime_get_sync(port->dev);
+- spin_lock_irq(&port->lock);
++ uart_port_lock_irq(port);
+
+ /*
+ * Update the per-port timeout.
+@@ -504,7 +504,7 @@ static void omap_8250_set_termios(struct
+ }
+ omap8250_restore_regs(up);
+
+- spin_unlock_irq(&up->port.lock);
++ uart_port_unlock_irq(&up->port);
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
+
+@@ -529,7 +529,7 @@ static void omap_8250_pm(struct uart_por
+ pm_runtime_get_sync(port->dev);
+
+ /* Synchronize UART_IER access against the console. */
+- spin_lock_irq(&port->lock);
++ uart_port_lock_irq(port);
+
+ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+ efr = serial_in(up, UART_EFR);
+@@ -541,7 +541,7 @@ static void omap_8250_pm(struct uart_por
+ serial_out(up, UART_EFR, efr);
+ serial_out(up, UART_LCR, 0);
+
+- spin_unlock_irq(&port->lock);
++ uart_port_unlock_irq(port);
+
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
+@@ -660,7 +660,7 @@ static irqreturn_t omap8250_irq(int irq,
+ unsigned long delay;
+
+ /* Synchronize UART_IER access against the console. */
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+ up->ier = port->serial_in(port, UART_IER);
+ if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
+ port->ops->stop_rx(port);
+@@ -670,7 +670,7 @@ static irqreturn_t omap8250_irq(int irq,
+ */
+ cancel_delayed_work(&up->overrun_backoff);
+ }
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+
+ delay = msecs_to_jiffies(up->overrun_backoff_time_ms);
+ schedule_delayed_work(&up->overrun_backoff, delay);
+@@ -717,10 +717,10 @@ static int omap_8250_startup(struct uart
+ }
+
+ /* Synchronize UART_IER access against the console. */
+- spin_lock_irq(&port->lock);
++ uart_port_lock_irq(port);
+ up->ier = UART_IER_RLSI | UART_IER_RDI;
+ serial_out(up, UART_IER, up->ier);
+- spin_unlock_irq(&port->lock);
++ uart_port_unlock_irq(port);
+
+ #ifdef CONFIG_PM
+ up->capabilities |= UART_CAP_RPM;
+@@ -733,9 +733,9 @@ static int omap_8250_startup(struct uart
+ serial_out(up, UART_OMAP_WER, priv->wer);
+
+ if (up->dma && !(priv->habit & UART_HAS_EFR2)) {
+- spin_lock_irq(&port->lock);
++ uart_port_lock_irq(port);
+ up->dma->rx_dma(up);
+- spin_unlock_irq(&port->lock);
++ uart_port_unlock_irq(port);
+ }
+
+ enable_irq(up->port.irq);
+@@ -761,10 +761,10 @@ static void omap_8250_shutdown(struct ua
+ serial_out(up, UART_OMAP_EFR2, 0x0);
+
+ /* Synchronize UART_IER access against the console. */
+- spin_lock_irq(&port->lock);
++ uart_port_lock_irq(port);
+ up->ier = 0;
+ serial_out(up, UART_IER, 0);
+- spin_unlock_irq(&port->lock);
++ uart_port_unlock_irq(port);
+ disable_irq_nosync(up->port.irq);
+ dev_pm_clear_wake_irq(port->dev);
+
+@@ -789,10 +789,10 @@ static void omap_8250_throttle(struct ua
+
+ pm_runtime_get_sync(port->dev);
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ port->ops->stop_rx(port);
+ priv->throttled = true;
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
+@@ -807,14 +807,14 @@ static void omap_8250_unthrottle(struct
+ pm_runtime_get_sync(port->dev);
+
+ /* Synchronize UART_IER access against the console. */
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ priv->throttled = false;
+ if (up->dma)
+ up->dma->rx_dma(up);
+ up->ier |= UART_IER_RLSI | UART_IER_RDI;
+ port->read_status_mask |= UART_LSR_DR;
+ serial_out(up, UART_IER, up->ier);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ pm_runtime_mark_last_busy(port->dev);
+ pm_runtime_put_autosuspend(port->dev);
+@@ -958,7 +958,7 @@ static void __dma_rx_complete(void *para
+ unsigned long flags;
+
+ /* Synchronize UART_IER access against the console. */
+- spin_lock_irqsave(&p->port.lock, flags);
++ uart_port_lock_irqsave(&p->port, &flags);
+
+ /*
+ * If the tx status is not DMA_COMPLETE, then this is a delayed
+@@ -967,7 +967,7 @@ static void __dma_rx_complete(void *para
+ */
+ if (dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state) !=
+ DMA_COMPLETE) {
+- spin_unlock_irqrestore(&p->port.lock, flags);
++ uart_port_unlock_irqrestore(&p->port, flags);
+ return;
+ }
+ __dma_rx_do_complete(p);
+@@ -978,7 +978,7 @@ static void __dma_rx_complete(void *para
+ omap_8250_rx_dma(p);
+ }
+
+- spin_unlock_irqrestore(&p->port.lock, flags);
++ uart_port_unlock_irqrestore(&p->port, flags);
+ }
+
+ static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
+@@ -1083,7 +1083,7 @@ static void omap_8250_dma_tx_complete(vo
+ dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr,
+ UART_XMIT_SIZE, DMA_TO_DEVICE);
+
+- spin_lock_irqsave(&p->port.lock, flags);
++ uart_port_lock_irqsave(&p->port, &flags);
+
+ dma->tx_running = 0;
+
+@@ -1112,7 +1112,7 @@ static void omap_8250_dma_tx_complete(vo
+ serial8250_set_THRI(p);
+ }
+
+- spin_unlock_irqrestore(&p->port.lock, flags);
++ uart_port_unlock_irqrestore(&p->port, flags);
+ }
+
+ static int omap_8250_tx_dma(struct uart_8250_port *p)
+@@ -1278,7 +1278,7 @@ static int omap_8250_dma_handle_irq(stru
+ return IRQ_HANDLED;
+ }
+
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+
+ status = serial_port_in(port, UART_LSR);
+
+@@ -1756,15 +1756,15 @@ static int omap8250_runtime_resume(struc
+ up = serial8250_get_port(priv->line);
+
+ if (up && omap8250_lost_context(up)) {
+- spin_lock_irq(&up->port.lock);
++ uart_port_lock_irq(&up->port);
+ omap8250_restore_regs(up);
+- spin_unlock_irq(&up->port.lock);
++ uart_port_unlock_irq(&up->port);
+ }
+
+ if (up && up->dma && up->dma->rxchan && !(priv->habit & UART_HAS_EFR2)) {
+- spin_lock_irq(&up->port.lock);
++ uart_port_lock_irq(&up->port);
+ omap_8250_rx_dma(up);
+- spin_unlock_irq(&up->port.lock);
++ uart_port_unlock_irq(&up->port);
+ }
+
+ priv->latency = priv->calc_latency;
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-14 02:41:51 +0000