OpenCloudOS-Kernel/include/linux/serial_core.h

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/*
* linux/drivers/char/serial_core.h
*
* Copyright (C) 2000 Deep Blue Solutions Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef LINUX_SERIAL_CORE_H
#define LINUX_SERIAL_CORE_H
#include <linux/serial.h>
/*
* The type definitions. These are from Ted Ts'o's serial.h
*/
#define PORT_UNKNOWN 0
#define PORT_8250 1
#define PORT_16450 2
#define PORT_16550 3
#define PORT_16550A 4
#define PORT_CIRRUS 5
#define PORT_16650 6
#define PORT_16650V2 7
#define PORT_16750 8
#define PORT_STARTECH 9
#define PORT_16C950 10
#define PORT_16654 11
#define PORT_16850 12
#define PORT_RSA 13
#define PORT_NS16550A 14
#define PORT_XSCALE 15
#define PORT_RM9000 16 /* PMC-Sierra RM9xxx internal UART */
#define PORT_OCTEON 17 /* Cavium OCTEON internal UART */
#define PORT_AR7 18 /* Texas Instruments AR7 internal UART */
#define PORT_U6_16550A 19 /* ST-Ericsson U6xxx internal UART */
#define PORT_MAX_8250 19 /* max port ID */
/*
* ARM specific type numbers. These are not currently guaranteed
* to be implemented, and will change in the future. These are
* separate so any additions to the old serial.c that occur before
* we are merged can be easily merged here.
*/
#define PORT_PXA 31
#define PORT_AMBA 32
#define PORT_CLPS711X 33
#define PORT_SA1100 34
#define PORT_UART00 35
#define PORT_21285 37
/* Sparc type numbers. */
#define PORT_SUNZILOG 38
#define PORT_SUNSAB 39
/* DEC */
#define PORT_DZ 46
#define PORT_ZS 47
/* Parisc type numbers. */
#define PORT_MUX 48
/* Atmel AT91 / AT32 SoC */
#define PORT_ATMEL 49
/* Macintosh Zilog type numbers */
#define PORT_MAC_ZILOG 50 /* m68k : not yet implemented */
#define PORT_PMAC_ZILOG 51
/* SH-SCI */
#define PORT_SCI 52
#define PORT_SCIF 53
#define PORT_IRDA 54
/* Samsung S3C2410 SoC and derivatives thereof */
#define PORT_S3C2410 55
/* SGI IP22 aka Indy / Challenge S / Indigo 2 */
#define PORT_IP22ZILOG 56
/* Sharp LH7a40x -- an ARM9 SoC series */
#define PORT_LH7A40X 57
/* PPC CPM type number */
#define PORT_CPM 58
/* MPC52xx type numbers */
#define PORT_MPC52xx 59
/* IBM icom */
#define PORT_ICOM 60
/* Samsung S3C2440 SoC */
#define PORT_S3C2440 61
/* Motorola i.MX SoC */
#define PORT_IMX 62
/* Marvell MPSC */
#define PORT_MPSC 63
/* TXX9 type number */
#define PORT_TXX9 64
/* NEC VR4100 series SIU/DSIU */
#define PORT_VR41XX_SIU 65
#define PORT_VR41XX_DSIU 66
/* Samsung S3C2400 SoC */
#define PORT_S3C2400 67
/* M32R SIO */
#define PORT_M32R_SIO 68
/*Digi jsm */
#define PORT_JSM 69
#define PORT_PNX8XXX 70
/* Hilscher netx */
#define PORT_NETX 71
/* SUN4V Hypervisor Console */
#define PORT_SUNHV 72
#define PORT_S3C2412 73
/* Xilinx uartlite */
#define PORT_UARTLITE 74
/* Blackfin bf5xx */
#define PORT_BFIN 75
/* Micrel KS8695 */
#define PORT_KS8695 76
/* Broadcom SB1250, etc. SOC */
#define PORT_SB1250_DUART 77
/* Freescale ColdFire */
#define PORT_MCF 78
/* Blackfin SPORT */
#define PORT_BFIN_SPORT 79
/* MN10300 on-chip UART numbers */
#define PORT_MN10300 80
#define PORT_MN10300_CTS 81
#define PORT_SC26XX 82
/* SH-SCI */
#define PORT_SCIFA 83
#define PORT_S3C6400 84
/* NWPSERIAL */
#define PORT_NWPSERIAL 85
/* MAX3100 */
#define PORT_MAX3100 86
/* Timberdale UART */
#define PORT_TIMBUART 87
/* Qualcomm MSM SoCs */
#define PORT_MSM 88
/* BCM63xx family SoCs */
#define PORT_BCM63XX 89
/* Aeroflex Gaisler GRLIB APBUART */
#define PORT_APBUART 90
/* Altera UARTs */
#define PORT_ALTERA_JTAGUART 91
#define PORT_ALTERA_UART 92
/* SH-SCI */
#define PORT_SCIFB 93
/* MAX3107 */
#define PORT_MAX3107 94
/* High Speed UART for Medfield */
#define PORT_MFD 95
#ifdef __KERNEL__
#include <linux/compiler.h>
#include <linux/interrupt.h>
#include <linux/circ_buf.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/mutex.h>
#include <linux/sysrq.h>
struct uart_port;
struct serial_struct;
struct device;
/*
* This structure describes all the operations that can be
* done on the physical hardware.
*/
struct uart_ops {
unsigned int (*tx_empty)(struct uart_port *);
void (*set_mctrl)(struct uart_port *, unsigned int mctrl);
unsigned int (*get_mctrl)(struct uart_port *);
void (*stop_tx)(struct uart_port *);
void (*start_tx)(struct uart_port *);
void (*send_xchar)(struct uart_port *, char ch);
void (*stop_rx)(struct uart_port *);
void (*enable_ms)(struct uart_port *);
void (*break_ctl)(struct uart_port *, int ctl);
int (*startup)(struct uart_port *);
void (*shutdown)(struct uart_port *);
void (*flush_buffer)(struct uart_port *);
void (*set_termios)(struct uart_port *, struct ktermios *new,
struct ktermios *old);
void (*set_ldisc)(struct uart_port *, int new);
void (*pm)(struct uart_port *, unsigned int state,
unsigned int oldstate);
int (*set_wake)(struct uart_port *, unsigned int state);
/*
* Return a string describing the type of the port
*/
const char *(*type)(struct uart_port *);
/*
* Release IO and memory resources used by the port.
* This includes iounmap if necessary.
*/
void (*release_port)(struct uart_port *);
/*
* Request IO and memory resources used by the port.
* This includes iomapping the port if necessary.
*/
int (*request_port)(struct uart_port *);
void (*config_port)(struct uart_port *, int);
int (*verify_port)(struct uart_port *, struct serial_struct *);
int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
#ifdef CONFIG_CONSOLE_POLL
void (*poll_put_char)(struct uart_port *, unsigned char);
int (*poll_get_char)(struct uart_port *);
#endif
};
#define NO_POLL_CHAR 0x00ff0000
#define UART_CONFIG_TYPE (1 << 0)
#define UART_CONFIG_IRQ (1 << 1)
struct uart_icount {
__u32 cts;
__u32 dsr;
__u32 rng;
__u32 dcd;
__u32 rx;
__u32 tx;
__u32 frame;
__u32 overrun;
__u32 parity;
__u32 brk;
__u32 buf_overrun;
};
typedef unsigned int __bitwise__ upf_t;
struct uart_port {
spinlock_t lock; /* port lock */
unsigned long iobase; /* in/out[bwl] */
unsigned char __iomem *membase; /* read/write[bwl] */
unsigned int (*serial_in)(struct uart_port *, int);
void (*serial_out)(struct uart_port *, int, int);
void (*set_termios)(struct uart_port *,
struct ktermios *new,
struct ktermios *old);
unsigned int irq; /* irq number */
unsigned long irqflags; /* irq flags */
unsigned int uartclk; /* base uart clock */
unsigned int fifosize; /* tx fifo size */
unsigned char x_char; /* xon/xoff char */
unsigned char regshift; /* reg offset shift */
unsigned char iotype; /* io access style */
unsigned char unused1;
#define UPIO_PORT (0)
#define UPIO_HUB6 (1)
#define UPIO_MEM (2)
#define UPIO_MEM32 (3)
#define UPIO_AU (4) /* Au1x00 type IO */
#define UPIO_TSI (5) /* Tsi108/109 type IO */
#define UPIO_DWAPB (6) /* DesignWare APB UART */
#define UPIO_RM9000 (7) /* RM9000 type IO */
unsigned int read_status_mask; /* driver specific */
unsigned int ignore_status_mask; /* driver specific */
struct uart_state *state; /* pointer to parent state */
struct uart_icount icount; /* statistics */
struct console *cons; /* struct console, if any */
#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
unsigned long sysrq; /* sysrq timeout */
#endif
upf_t flags;
#define UPF_FOURPORT ((__force upf_t) (1 << 1))
#define UPF_SAK ((__force upf_t) (1 << 2))
#define UPF_SPD_MASK ((__force upf_t) (0x1030))
#define UPF_SPD_HI ((__force upf_t) (0x0010))
#define UPF_SPD_VHI ((__force upf_t) (0x0020))
#define UPF_SPD_CUST ((__force upf_t) (0x0030))
#define UPF_SPD_SHI ((__force upf_t) (0x1000))
#define UPF_SPD_WARP ((__force upf_t) (0x1010))
#define UPF_SKIP_TEST ((__force upf_t) (1 << 6))
#define UPF_AUTO_IRQ ((__force upf_t) (1 << 7))
#define UPF_HARDPPS_CD ((__force upf_t) (1 << 11))
#define UPF_LOW_LATENCY ((__force upf_t) (1 << 13))
#define UPF_BUGGY_UART ((__force upf_t) (1 << 14))
8250: fix boot hang with serial console when using with Serial Over Lan port Intel 8257x Ethernet boards have a feature called Serial Over Lan. This feature works by emulating a serial port, and it is detected by kernel as a normal 8250 port. However, this emulation is not perfect, as also noticed on changeset 7500b1f602aad75901774a67a687ee985d85893f. Before this patch, the kernel were trying to check if the serial TX is capable of work using IRQ's. This were done with a code similar this: serial_outp(up, UART_IER, UART_IER_THRI); lsr = serial_in(up, UART_LSR); iir = serial_in(up, UART_IIR); serial_outp(up, UART_IER, 0); if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) up->bugs |= UART_BUG_TXEN; This works fine for other 8250 ports, but, on 8250-emulated SoL port, the chip is a little lazy to down UART_IIR_NO_INT at UART_IIR register. Due to that, UART_BUG_TXEN is sometimes enabled. However, as TX IRQ keeps working, and the TX polling is now enabled, the driver miss-interprets the IRQ received later, hanging up the machine until a key is pressed at the serial console. This is the 6 version of this patch. Previous versions were trying to introduce a large enough delay between serial_outp and serial_in(up, UART_IIR), but not taking forever. However, the needed delay couldn't be safely determined. At the experimental tests, a delay of 1us solves most of the cases, but still hangs sometimes. Increasing the delay to 5us was better, but still doesn't solve. A very high delay of 50 ms seemed to work every time. However, poking around with delays and pray for it to be enough doesn't seem to be a good approach, even for a quirk. So, instead of playing with random large arbitrary delays, let's just disable UART_BUG_TXEN for all SoL ports. [akpm@linux-foundation.org: fix warnings] Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-21 07:38:52 +08:00
#define UPF_NO_TXEN_TEST ((__force upf_t) (1 << 15))
#define UPF_MAGIC_MULTIPLIER ((__force upf_t) (1 << 16))
#define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
#define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
/* The exact UART type is known and should not be probed. */
#define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
#define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
#define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
#define UPF_DEAD ((__force upf_t) (1 << 30))
#define UPF_IOREMAP ((__force upf_t) (1 << 31))
#define UPF_CHANGE_MASK ((__force upf_t) (0x17fff))
#define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
unsigned int mctrl; /* current modem ctrl settings */
unsigned int timeout; /* character-based timeout */
unsigned int type; /* port type */
const struct uart_ops *ops;
unsigned int custom_divisor;
unsigned int line; /* port index */
resource_size_t mapbase; /* for ioremap */
struct device *dev; /* parent device */
unsigned char hub6; /* this should be in the 8250 driver */
unsigned char suspended;
unsigned char unused[2];
void *private_data; /* generic platform data pointer */
};
/*
* This is the state information which is persistent across opens.
*/
struct uart_state {
struct tty_port port;
int pm_state;
struct circ_buf xmit;
struct tasklet_struct tlet;
struct uart_port *uart_port;
};
#define UART_XMIT_SIZE PAGE_SIZE
/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256
struct module;
struct tty_driver;
struct uart_driver {
struct module *owner;
const char *driver_name;
const char *dev_name;
int major;
int minor;
int nr;
struct console *cons;
/*
* these are private; the low level driver should not
* touch these; they should be initialised to NULL
*/
struct uart_state *state;
struct tty_driver *tty_driver;
};
void uart_write_wakeup(struct uart_port *port);
/*
* Baud rate helpers.
*/
void uart_update_timeout(struct uart_port *port, unsigned int cflag,
unsigned int baud);
unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
struct ktermios *old, unsigned int min,
unsigned int max);
unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud);
/* Base timer interval for polling */
static inline int uart_poll_timeout(struct uart_port *port)
{
int timeout = port->timeout;
return timeout > 6 ? (timeout / 2 - 2) : 1;
}
/*
* Console helpers.
*/
struct uart_port *uart_get_console(struct uart_port *ports, int nr,
struct console *c);
void uart_parse_options(char *options, int *baud, int *parity, int *bits,
int *flow);
int uart_set_options(struct uart_port *port, struct console *co, int baud,
int parity, int bits, int flow);
struct tty_driver *uart_console_device(struct console *co, int *index);
void uart_console_write(struct uart_port *port, const char *s,
unsigned int count,
void (*putchar)(struct uart_port *, int));
/*
* Port/driver registration/removal
*/
int uart_register_driver(struct uart_driver *uart);
void uart_unregister_driver(struct uart_driver *uart);
int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
int uart_match_port(struct uart_port *port1, struct uart_port *port2);
/*
* Power Management
*/
int uart_suspend_port(struct uart_driver *reg, struct uart_port *port);
int uart_resume_port(struct uart_driver *reg, struct uart_port *port);
#define uart_circ_empty(circ) ((circ)->head == (circ)->tail)
#define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0)
#define uart_circ_chars_pending(circ) \
(CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
#define uart_circ_chars_free(circ) \
(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
static inline int uart_tx_stopped(struct uart_port *port)
{
struct tty_struct *tty = port->state->port.tty;
if(tty->stopped || tty->hw_stopped)
return 1;
return 0;
}
/*
* The following are helper functions for the low level drivers.
*/
static inline int
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 21:55:46 +08:00
uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
{
#ifdef SUPPORT_SYSRQ
if (port->sysrq) {
if (ch && time_before(jiffies, port->sysrq)) {
handle_sysrq(ch);
port->sysrq = 0;
return 1;
}
port->sysrq = 0;
}
#endif
return 0;
}
#ifndef SUPPORT_SYSRQ
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 21:55:46 +08:00
#define uart_handle_sysrq_char(port,ch) uart_handle_sysrq_char(port, 0)
#endif
/*
* We do the SysRQ and SAK checking like this...
*/
static inline int uart_handle_break(struct uart_port *port)
{
struct uart_state *state = port->state;
#ifdef SUPPORT_SYSRQ
if (port->cons && port->cons->index == port->line) {
if (!port->sysrq) {
port->sysrq = jiffies + HZ*5;
return 1;
}
port->sysrq = 0;
}
#endif
if (port->flags & UPF_SAK)
do_SAK(state->port.tty);
return 0;
}
/**
* uart_handle_dcd_change - handle a change of carrier detect state
* @uport: uart_port structure for the open port
* @status: new carrier detect status, nonzero if active
*/
static inline void
uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
{
struct uart_state *state = uport->state;
struct tty_port *port = &state->port;
struct tty_ldisc *ld = tty_ldisc_ref(port->tty);
struct timespec ts;
if (ld && ld->ops->dcd_change)
getnstimeofday(&ts);
uport->icount.dcd++;
#ifdef CONFIG_HARD_PPS
if ((uport->flags & UPF_HARDPPS_CD) && status)
hardpps();
#endif
if (port->flags & ASYNC_CHECK_CD) {
if (status)
wake_up_interruptible(&port->open_wait);
else if (port->tty)
tty_hangup(port->tty);
}
if (ld && ld->ops->dcd_change)
ld->ops->dcd_change(port->tty, status, &ts);
if (ld)
tty_ldisc_deref(ld);
}
/**
* uart_handle_cts_change - handle a change of clear-to-send state
* @uport: uart_port structure for the open port
* @status: new clear to send status, nonzero if active
*/
static inline void
uart_handle_cts_change(struct uart_port *uport, unsigned int status)
{
struct tty_port *port = &uport->state->port;
struct tty_struct *tty = port->tty;
uport->icount.cts++;
if (port->flags & ASYNC_CTS_FLOW) {
if (tty->hw_stopped) {
if (status) {
tty->hw_stopped = 0;
uport->ops->start_tx(uport);
uart_write_wakeup(uport);
}
} else {
if (!status) {
tty->hw_stopped = 1;
uport->ops->stop_tx(uport);
}
}
}
}
#include <linux/tty_flip.h>
static inline void
uart_insert_char(struct uart_port *port, unsigned int status,
unsigned int overrun, unsigned int ch, unsigned int flag)
{
struct tty_struct *tty = port->state->port.tty;
if ((status & port->ignore_status_mask & ~overrun) == 0)
tty_insert_flip_char(tty, ch, flag);
/*
* Overrun is special. Since it's reported immediately,
* it doesn't affect the current character.
*/
if (status & ~port->ignore_status_mask & overrun)
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
}
/*
* UART_ENABLE_MS - determine if port should enable modem status irqs
*/
#define UART_ENABLE_MS(port,cflag) ((port)->flags & UPF_HARDPPS_CD || \
(cflag) & CRTSCTS || \
!((cflag) & CLOCAL))
#endif
#endif /* LINUX_SERIAL_CORE_H */