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-rw-r--r--debian/patches-rt/0064-serial-stm32-Use-port-lock-wrappers.patch184
1 files changed, 184 insertions, 0 deletions
diff --git a/debian/patches-rt/0064-serial-stm32-Use-port-lock-wrappers.patch b/debian/patches-rt/0064-serial-stm32-Use-port-lock-wrappers.patch
new file mode 100644
index 000000000..cc261d43e
--- /dev/null
+++ b/debian/patches-rt/0064-serial-stm32-Use-port-lock-wrappers.patch
@@ -0,0 +1,184 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:44:21 +0206
+Subject: [PATCH 064/134] serial: stm32: 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/20230914183831.587273-65-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/stm32-usart.c | 38 +++++++++++++++++++-------------------
+ 1 file changed, 19 insertions(+), 19 deletions(-)
+
+--- a/drivers/tty/serial/stm32-usart.c
++++ b/drivers/tty/serial/stm32-usart.c
+@@ -537,7 +537,7 @@ static void stm32_usart_rx_dma_complete(
+ unsigned int size;
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ size = stm32_usart_receive_chars(port, false);
+ uart_unlock_and_check_sysrq_irqrestore(port, flags);
+ if (size)
+@@ -643,9 +643,9 @@ static void stm32_usart_tx_dma_complete(
+ stm32_usart_tx_dma_terminate(stm32port);
+
+ /* Let's see if we have pending data to send */
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ stm32_usart_transmit_chars(port);
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static void stm32_usart_tx_interrupt_enable(struct uart_port *port)
+@@ -889,7 +889,7 @@ static irqreturn_t stm32_usart_interrupt
+ if (!stm32_port->throttled) {
+ if (((sr & USART_SR_RXNE) && !stm32_usart_rx_dma_started(stm32_port)) ||
+ ((sr & USART_SR_ERR_MASK) && stm32_usart_rx_dma_started(stm32_port))) {
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+ size = stm32_usart_receive_chars(port, false);
+ uart_unlock_and_check_sysrq(port);
+ if (size)
+@@ -898,14 +898,14 @@ static irqreturn_t stm32_usart_interrupt
+ }
+
+ if ((sr & USART_SR_TXE) && !(stm32_port->tx_ch)) {
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+ stm32_usart_transmit_chars(port);
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+ }
+
+ /* Receiver timeout irq for DMA RX */
+ if (stm32_usart_rx_dma_started(stm32_port) && !stm32_port->throttled) {
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+ size = stm32_usart_receive_chars(port, false);
+ uart_unlock_and_check_sysrq(port);
+ if (size)
+@@ -993,7 +993,7 @@ static void stm32_usart_throttle(struct
+ const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ /*
+ * Pause DMA transfer, so the RX data gets queued into the FIFO.
+@@ -1006,7 +1006,7 @@ static void stm32_usart_throttle(struct
+ stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
+
+ stm32_port->throttled = true;
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ /* Unthrottle the remote, the input buffer can now accept data. */
+@@ -1016,7 +1016,7 @@ static void stm32_usart_unthrottle(struc
+ const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+ unsigned long flags;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ stm32_usart_set_bits(port, ofs->cr1, stm32_port->cr1_irq);
+ if (stm32_port->cr3_irq)
+ stm32_usart_set_bits(port, ofs->cr3, stm32_port->cr3_irq);
+@@ -1030,7 +1030,7 @@ static void stm32_usart_unthrottle(struc
+ if (stm32_port->rx_ch)
+ stm32_usart_rx_dma_start_or_resume(port);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ /* Receive stop */
+@@ -1158,7 +1158,7 @@ static void stm32_usart_set_termios(stru
+
+ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 8);
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr,
+ isr,
+@@ -1349,7 +1349,7 @@ static void stm32_usart_set_termios(stru
+ writel_relaxed(cr1, port->membase + ofs->cr1);
+
+ stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ /* Handle modem control interrupts */
+ if (UART_ENABLE_MS(port, termios->c_cflag))
+@@ -1399,9 +1399,9 @@ static void stm32_usart_pm(struct uart_p
+ pm_runtime_get_sync(port->dev);
+ break;
+ case UART_PM_STATE_OFF:
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ pm_runtime_put_sync(port->dev);
+ break;
+ }
+@@ -1884,9 +1884,9 @@ static void stm32_usart_console_write(st
+ int locked = 1;
+
+ if (oops_in_progress)
+- locked = spin_trylock_irqsave(&port->lock, flags);
++ locked = uart_port_trylock_irqsave(port, &flags);
+ else
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ /* Save and disable interrupts, enable the transmitter */
+ old_cr1 = readl_relaxed(port->membase + ofs->cr1);
+@@ -1900,7 +1900,7 @@ static void stm32_usart_console_write(st
+ writel_relaxed(old_cr1, port->membase + ofs->cr1);
+
+ if (locked)
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static int stm32_usart_console_setup(struct console *co, char *options)
+@@ -2035,7 +2035,7 @@ static int __maybe_unused stm32_usart_se
+ * low-power mode.
+ */
+ if (stm32_port->rx_ch) {
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ /* Poll data from DMA RX buffer if any */
+ if (!stm32_usart_rx_dma_pause(stm32_port))
+ size += stm32_usart_receive_chars(port, true);
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-30 10:09:45 +0000