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Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0028-serial-icom-Use-port-lock-wrappers.patch | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/debian/patches-rt/0028-serial-icom-Use-port-lock-wrappers.patch b/debian/patches-rt/0028-serial-icom-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..da765879c --- /dev/null +++ b/debian/patches-rt/0028-serial-icom-Use-port-lock-wrappers.patch @@ -0,0 +1,151 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:45 +0206 +Subject: [PATCH 028/134] serial: icom: 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/20230914183831.587273-29-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/icom.c | 26 +++++++++++++------------- + 1 file changed, 13 insertions(+), 13 deletions(-) + +--- a/drivers/tty/serial/icom.c ++++ b/drivers/tty/serial/icom.c +@@ -929,7 +929,7 @@ static inline void check_modem_status(st + char delta_status; + unsigned char status; + +- spin_lock(&icom_port->uart_port.lock); ++ uart_port_lock(&icom_port->uart_port); + + /*modem input register */ + status = readb(&icom_port->dram->isr); +@@ -951,7 +951,7 @@ static inline void check_modem_status(st + port.delta_msr_wait); + old_status = status; + } +- spin_unlock(&icom_port->uart_port.lock); ++ uart_port_unlock(&icom_port->uart_port); + } + + static void xmit_interrupt(u16 port_int_reg, struct icom_port *icom_port) +@@ -1093,7 +1093,7 @@ static void process_interrupt(u16 port_i + struct icom_port *icom_port) + { + +- spin_lock(&icom_port->uart_port.lock); ++ uart_port_lock(&icom_port->uart_port); + trace(icom_port, "INTERRUPT", port_int_reg); + + if (port_int_reg & (INT_XMIT_COMPLETED | INT_XMIT_DISABLED)) +@@ -1102,7 +1102,7 @@ static void process_interrupt(u16 port_i + if (port_int_reg & INT_RCV_COMPLETED) + recv_interrupt(port_int_reg, icom_port); + +- spin_unlock(&icom_port->uart_port.lock); ++ uart_port_unlock(&icom_port->uart_port); + } + + static irqreturn_t icom_interrupt(int irq, void *dev_id) +@@ -1186,14 +1186,14 @@ static unsigned int icom_tx_empty(struct + int ret; + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + if (le16_to_cpu(icom_port->statStg->xmit[0].flags) & + SA_FLAGS_READY_TO_XMIT) + ret = TIOCSER_TEMT; + else + ret = 0; + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + return ret; + } + +@@ -1276,7 +1276,7 @@ static void icom_send_xchar(struct uart_ + + /* wait .1 sec to send char */ + for (index = 0; index < 10; index++) { +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + xdata = readb(&icom_port->dram->xchar); + if (xdata == 0x00) { + trace(icom_port, "QUICK_WRITE", 0); +@@ -1284,10 +1284,10 @@ static void icom_send_xchar(struct uart_ + + /* flush write operation */ + xdata = readb(&icom_port->dram->xchar); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + break; + } +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + msleep(10); + } + } +@@ -1307,7 +1307,7 @@ static void icom_break(struct uart_port + unsigned char cmdReg; + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + trace(icom_port, "BREAK", 0); + cmdReg = readb(&icom_port->dram->CmdReg); + if (break_state == -1) { +@@ -1315,7 +1315,7 @@ static void icom_break(struct uart_port + } else { + writeb(cmdReg & ~CMD_SND_BREAK, &icom_port->dram->CmdReg); + } +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static int icom_open(struct uart_port *port) +@@ -1365,7 +1365,7 @@ static void icom_set_termios(struct uart + unsigned long offset; + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + trace(icom_port, "CHANGE_SPEED", 0); + + cflag = termios->c_cflag; +@@ -1516,7 +1516,7 @@ static void icom_set_termios(struct uart + trace(icom_port, "XR_ENAB", 0); + writeb(CMD_XMIT_RCV_ENABLE, &icom_port->dram->CmdReg); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static const char *icom_type(struct uart_port *port) |