diff options
Diffstat (limited to 'debian/patches-rt/0046-serial-pic32-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0046-serial-pic32-Use-port-lock-wrappers.patch | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/debian/patches-rt/0046-serial-pic32-Use-port-lock-wrappers.patch b/debian/patches-rt/0046-serial-pic32-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..7cb8da7d86 --- /dev/null +++ b/debian/patches-rt/0046-serial-pic32-Use-port-lock-wrappers.patch @@ -0,0 +1,118 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:03 +0206 +Subject: [PATCH 046/134] serial: pic32: 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/20230914183831.587273-47-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/pic32_uart.c | 20 ++++++++++---------- + 1 file changed, 10 insertions(+), 10 deletions(-) + +--- a/drivers/tty/serial/pic32_uart.c ++++ b/drivers/tty/serial/pic32_uart.c +@@ -243,7 +243,7 @@ static void pic32_uart_break_ctl(struct + struct pic32_sport *sport = to_pic32_sport(port); + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + if (ctl) + pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA), +@@ -252,7 +252,7 @@ static void pic32_uart_break_ctl(struct + pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), + PIC32_UART_STA_UTXBRK); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + /* get port type in string format */ +@@ -274,7 +274,7 @@ static void pic32_uart_do_rx(struct uart + */ + max_count = PIC32_UART_RX_FIFO_DEPTH; + +- spin_lock(&port->lock); ++ uart_port_lock(port); + + tty = &port->state->port; + +@@ -331,7 +331,7 @@ static void pic32_uart_do_rx(struct uart + + } while (--max_count); + +- spin_unlock(&port->lock); ++ uart_port_unlock(port); + + tty_flip_buffer_push(tty); + } +@@ -410,9 +410,9 @@ static irqreturn_t pic32_uart_tx_interru + struct uart_port *port = dev_id; + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + pic32_uart_do_tx(port); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + return IRQ_HANDLED; + } +@@ -580,9 +580,9 @@ static void pic32_uart_shutdown(struct u + unsigned long flags; + + /* disable uart */ +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + pic32_uart_dsbl_and_mask(port); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + clk_disable_unprepare(sport->clk); + + /* free all 3 interrupts for this UART */ +@@ -604,7 +604,7 @@ static void pic32_uart_set_termios(struc + unsigned int quot; + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + /* disable uart and mask all interrupts while changing speed */ + pic32_uart_dsbl_and_mask(port); +@@ -672,7 +672,7 @@ static void pic32_uart_set_termios(struc + /* enable uart */ + pic32_uart_en_and_unmask(port); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + /* serial core request to claim uart iomem */ |