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-rw-r--r--debian/patches-rt/0041-serial-msm-Use-port-lock-wrappers.patch185
1 files changed, 185 insertions, 0 deletions
diff --git a/debian/patches-rt/0041-serial-msm-Use-port-lock-wrappers.patch b/debian/patches-rt/0041-serial-msm-Use-port-lock-wrappers.patch
new file mode 100644
index 0000000000..89b8453303
--- /dev/null
+++ b/debian/patches-rt/0041-serial-msm-Use-port-lock-wrappers.patch
@@ -0,0 +1,185 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 14 Sep 2023 20:43:58 +0206
+Subject: [PATCH 041/134] serial: msm: 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>
+Reviewed-by: Bjorn Andersson <quic_bjorande@quicinc.com>
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+Link: https://lore.kernel.org/r/20230914183831.587273-42-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/msm_serial.c | 38 +++++++++++++++++++-------------------
+ 1 file changed, 19 insertions(+), 19 deletions(-)
+
+--- a/drivers/tty/serial/msm_serial.c
++++ b/drivers/tty/serial/msm_serial.c
+@@ -444,7 +444,7 @@ static void msm_complete_tx_dma(void *ar
+ unsigned int count;
+ u32 val;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ /* Already stopped */
+ if (!dma->count)
+@@ -476,7 +476,7 @@ static void msm_complete_tx_dma(void *ar
+
+ msm_handle_tx(port);
+ done:
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count)
+@@ -549,7 +549,7 @@ static void msm_complete_rx_dma(void *ar
+ unsigned long flags;
+ u32 val;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ /* Already stopped */
+ if (!dma->count)
+@@ -587,16 +587,16 @@ static void msm_complete_rx_dma(void *ar
+ if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK))
+ flag = TTY_NORMAL;
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ sysrq = uart_handle_sysrq_char(port, dma->virt[i]);
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ if (!sysrq)
+ tty_insert_flip_char(tport, dma->virt[i], flag);
+ }
+
+ msm_start_rx_dma(msm_port);
+ done:
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ if (count)
+ tty_flip_buffer_push(tport);
+@@ -762,9 +762,9 @@ static void msm_handle_rx_dm(struct uart
+ if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK))
+ flag = TTY_NORMAL;
+
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+ sysrq = uart_handle_sysrq_char(port, buf[i]);
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+ if (!sysrq)
+ tty_insert_flip_char(tport, buf[i], flag);
+ }
+@@ -824,9 +824,9 @@ static void msm_handle_rx(struct uart_po
+ else if (sr & MSM_UART_SR_PAR_FRAME_ERR)
+ flag = TTY_FRAME;
+
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+ sysrq = uart_handle_sysrq_char(port, c);
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+ if (!sysrq)
+ tty_insert_flip_char(tport, c, flag);
+ }
+@@ -951,7 +951,7 @@ static irqreturn_t msm_uart_irq(int irq,
+ unsigned int misr;
+ u32 val;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ misr = msm_read(port, MSM_UART_MISR);
+ msm_write(port, 0, MSM_UART_IMR); /* disable interrupt */
+
+@@ -983,7 +983,7 @@ static irqreturn_t msm_uart_irq(int irq,
+ msm_handle_delta_cts(port);
+
+ msm_write(port, msm_port->imr, MSM_UART_IMR); /* restore interrupt */
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ return IRQ_HANDLED;
+ }
+@@ -1128,13 +1128,13 @@ static int msm_set_baud_rate(struct uart
+ unsigned long flags, rate;
+
+ flags = *saved_flags;
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+
+ entry = msm_find_best_baud(port, baud, &rate);
+ clk_set_rate(msm_port->clk, rate);
+ baud = rate / 16 / entry->divisor;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+ *saved_flags = flags;
+ port->uartclk = rate;
+
+@@ -1266,7 +1266,7 @@ static void msm_set_termios(struct uart_
+ unsigned long flags;
+ unsigned int baud, mr;
+
+- spin_lock_irqsave(&port->lock, flags);
++ uart_port_lock_irqsave(port, &flags);
+
+ if (dma->chan) /* Terminate if any */
+ msm_stop_dma(port, dma);
+@@ -1338,7 +1338,7 @@ static void msm_set_termios(struct uart_
+ /* Try to use DMA */
+ msm_start_rx_dma(msm_port);
+
+- spin_unlock_irqrestore(&port->lock, flags);
++ uart_port_unlock_irqrestore(port, flags);
+ }
+
+ static const char *msm_type(struct uart_port *port)
+@@ -1620,9 +1620,9 @@ static void __msm_console_write(struct u
+ if (port->sysrq)
+ locked = 0;
+ else if (oops_in_progress)
+- locked = spin_trylock(&port->lock);
++ locked = uart_port_trylock(port);
+ else
+- spin_lock(&port->lock);
++ uart_port_lock(port);
+
+ if (is_uartdm)
+ msm_reset_dm_count(port, count);
+@@ -1661,7 +1661,7 @@ static void __msm_console_write(struct u
+ }
+
+ if (locked)
+- spin_unlock(&port->lock);
++ uart_port_unlock(port);
+
+ local_irq_restore(flags);
+ }
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 08:23:17 +0000