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Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0052-serial-sa1100-Use-port-lock-wrappers.patch | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/debian/patches-rt/0052-serial-sa1100-Use-port-lock-wrappers.patch b/debian/patches-rt/0052-serial-sa1100-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..2f8073a48 --- /dev/null +++ b/debian/patches-rt/0052-serial-sa1100-Use-port-lock-wrappers.patch @@ -0,0 +1,117 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:09 +0206 +Subject: [PATCH 052/134] serial: sa1100: 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/20230914183831.587273-53-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/sa1100.c | 20 ++++++++++---------- + 1 file changed, 10 insertions(+), 10 deletions(-) + +--- a/drivers/tty/serial/sa1100.c ++++ b/drivers/tty/serial/sa1100.c +@@ -115,9 +115,9 @@ static void sa1100_timeout(struct timer_ + unsigned long flags; + + if (sport->port.state) { +- spin_lock_irqsave(&sport->port.lock, flags); ++ uart_port_lock_irqsave(&sport->port, &flags); + sa1100_mctrl_check(sport); +- spin_unlock_irqrestore(&sport->port.lock, flags); ++ uart_port_unlock_irqrestore(&sport->port, flags); + + mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT); + } +@@ -247,7 +247,7 @@ static irqreturn_t sa1100_int(int irq, v + struct sa1100_port *sport = dev_id; + unsigned int status, pass_counter = 0; + +- spin_lock(&sport->port.lock); ++ uart_port_lock(&sport->port); + status = UART_GET_UTSR0(sport); + status &= SM_TO_UTSR0(sport->port.read_status_mask) | ~UTSR0_TFS; + do { +@@ -276,7 +276,7 @@ static irqreturn_t sa1100_int(int irq, v + status &= SM_TO_UTSR0(sport->port.read_status_mask) | + ~UTSR0_TFS; + } while (status & (UTSR0_TFS | UTSR0_RFS | UTSR0_RID)); +- spin_unlock(&sport->port.lock); ++ uart_port_unlock(&sport->port); + + return IRQ_HANDLED; + } +@@ -321,14 +321,14 @@ static void sa1100_break_ctl(struct uart + unsigned long flags; + unsigned int utcr3; + +- spin_lock_irqsave(&sport->port.lock, flags); ++ uart_port_lock_irqsave(&sport->port, &flags); + utcr3 = UART_GET_UTCR3(sport); + if (break_state == -1) + utcr3 |= UTCR3_BRK; + else + utcr3 &= ~UTCR3_BRK; + UART_PUT_UTCR3(sport, utcr3); +- spin_unlock_irqrestore(&sport->port.lock, flags); ++ uart_port_unlock_irqrestore(&sport->port, flags); + } + + static int sa1100_startup(struct uart_port *port) +@@ -354,9 +354,9 @@ static int sa1100_startup(struct uart_po + /* + * Enable modem status interrupts + */ +- spin_lock_irq(&sport->port.lock); ++ uart_port_lock_irq(&sport->port); + sa1100_enable_ms(&sport->port); +- spin_unlock_irq(&sport->port.lock); ++ uart_port_unlock_irq(&sport->port); + + return 0; + } +@@ -423,7 +423,7 @@ sa1100_set_termios(struct uart_port *por + + del_timer_sync(&sport->timer); + +- spin_lock_irqsave(&sport->port.lock, flags); ++ uart_port_lock_irqsave(&sport->port, &flags); + + sport->port.read_status_mask &= UTSR0_TO_SM(UTSR0_TFS); + sport->port.read_status_mask |= UTSR1_TO_SM(UTSR1_ROR); +@@ -485,7 +485,7 @@ sa1100_set_termios(struct uart_port *por + if (UART_ENABLE_MS(&sport->port, termios->c_cflag)) + sa1100_enable_ms(&sport->port); + +- spin_unlock_irqrestore(&sport->port.lock, flags); ++ uart_port_unlock_irqrestore(&sport->port, flags); + } + + static const char *sa1100_type(struct uart_port *port) |