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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 18:50:40 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 18:50:59 +0000
commitba6b167af6ee5e63ca79ad22e7719644aed12b2c (patch)
tree62272cbe2fb256ecb90fa6e2cbfa509541954d28 /debian/patches-rt/0002-serial-ar933x-Use-uart_prepare_sysrq_char.patch
parentMerging upstream version 6.8.9. (diff)
downloadlinux-ba6b167af6ee5e63ca79ad22e7719644aed12b2c.tar.xz
linux-ba6b167af6ee5e63ca79ad22e7719644aed12b2c.zip
Merging debian version 6.8.9-1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'debian/patches-rt/0002-serial-ar933x-Use-uart_prepare_sysrq_char.patch')
-rw-r--r--debian/patches-rt/0002-serial-ar933x-Use-uart_prepare_sysrq_char.patch68
1 files changed, 68 insertions, 0 deletions
diff --git a/debian/patches-rt/0002-serial-ar933x-Use-uart_prepare_sysrq_char.patch b/debian/patches-rt/0002-serial-ar933x-Use-uart_prepare_sysrq_char.patch
new file mode 100644
index 0000000000..f8f97abf10
--- /dev/null
+++ b/debian/patches-rt/0002-serial-ar933x-Use-uart_prepare_sysrq_char.patch
@@ -0,0 +1,68 @@
+From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Date: Fri, 1 Mar 2024 22:45:15 +0100
+Subject: [PATCH 02/18] serial: ar933x: Use uart_prepare_sysrq_char().
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.8/older/patches-6.8.2-rt11.tar.xz
+
+The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
+The driver splits the locking function into two parts: local_irq_save() and
+uart_port_lock() and this breaks PREEMPT_RT.
+
+Delay handling sysrq until port lock is dropped.
+Remove the special case in the console write routine an always use the
+complete locking function.
+
+Link: https://lore.kernel.org/r/20240301215246.891055-3-bigeasy@linutronix.de
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ drivers/tty/serial/ar933x_uart.c | 18 ++++++------------
+ 1 file changed, 6 insertions(+), 12 deletions(-)
+
+--- a/drivers/tty/serial/ar933x_uart.c
++++ b/drivers/tty/serial/ar933x_uart.c
+@@ -378,7 +378,7 @@ static void ar933x_uart_rx_chars(struct
+ up->port.icount.rx++;
+ ch = rdata & AR933X_UART_DATA_TX_RX_MASK;
+
+- if (uart_handle_sysrq_char(&up->port, ch))
++ if (uart_prepare_sysrq_char(&up->port, ch))
+ continue;
+
+ if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0)
+@@ -468,7 +468,7 @@ static irqreturn_t ar933x_uart_interrupt
+ ar933x_uart_tx_chars(up);
+ }
+
+- uart_port_unlock(&up->port);
++ uart_unlock_and_check_sysrq(&up->port);
+
+ return IRQ_HANDLED;
+ }
+@@ -627,14 +627,10 @@ static void ar933x_uart_console_write(st
+ unsigned int int_en;
+ int locked = 1;
+
+- local_irq_save(flags);
+-
+- if (up->port.sysrq)
+- locked = 0;
+- else if (oops_in_progress)
+- locked = uart_port_trylock(&up->port);
++ if (oops_in_progress)
++ locked = uart_port_trylock_irqsave(&up->port, &flags);
+ else
+- uart_port_lock(&up->port);
++ uart_port_lock_irqsave(&up->port, &flags);
+
+ /*
+ * First save the IER then disable the interrupts
+@@ -654,9 +650,7 @@ static void ar933x_uart_console_write(st
+ ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS);
+
+ if (locked)
+- uart_port_unlock(&up->port);
+-
+- local_irq_restore(flags);
++ uart_port_unlock_irqrestore(&up->port, flags);
+ }
+
+ static int ar933x_uart_console_setup(struct console *co, char *options)