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This patch set adds the PPS support into Linux. PPS means "pulse per second" and its API is specified by RFC 2783 (Pulse-Per-Second API for UNIX-like Operating Systems, Version 1.0). The code has been tested with the NTPD program (http://www.eecis.udel.edu/~mills/ntp/html/index.html) and several GPS antennae. Changelog RESUBMIT 6 -> 7: * A new line discipline has been added in order to leave untouched the serial ports code (as suggested by Alan). * n_tty.c exports only GPL symbols. * ioctl numbers fixed in order to avoid any conflicts. * Last patch (0010-PPS-low-level-IRQ-timestamps-recording.patch) implements low level IRQs timestamps recording which mproves PPS precision but can be dropped for kernel inclusion! As suggested by Alan: "After that is sorted/merged we can come back to working out the best way to improve the IRQ and HARDPPS hacks." Rodolfo -- b/Documentation/ABI/testing/sysfs-pps | 73 +++++++ b/Documentation/ioctl-number.txt | 2 b/Documentation/pps/Makefile | 28 ++ b/Documentation/pps/pps.txt | 172 +++++++++++++++++ b/Documentation/pps/ppsfind | 17 + b/Documentation/pps/ppsldisc.c | 46 ++++ b/Documentation/pps/ppstest.c | 151 +++++++++++++++ b/Documentation/pps/timepps.h | 195 +++++++++++++++++++ b/Documentation/tty.txt | 4 b/MAINTAINERS | 7 b/arch/x86/kernel/irq_32.c | 17 + b/arch/x86/kernel/irq_64.c | 21 +- b/drivers/Kconfig | 2 b/drivers/Makefile | 1 b/drivers/char/lp.c | 61 ++++++ b/drivers/char/n_tty.c | 54 +++-- b/drivers/pps/Kconfig | 33 +++ b/drivers/pps/Makefile | 8 b/drivers/pps/clients/Kconfig | 18 + b/drivers/pps/clients/Makefile | 9 b/drivers/pps/clients/ktimer.c | 124 ++++++++++++ ...
This patch adds the kernel side of the PPS support currently named "LinuxPPS". PPS means "pulse per second" and a PPS source is just a device which provides a high precision signal each second so that an application can use it to adjust system clock time. Common use is the combination of the NTPD as userland program with a GPS receiver as PPS source to obtain a wallclock-time with sub-millisecond synchronisation to UTC. To obtain this goal the userland programs shoud use the PPS API specification (RFC 2783 - Pulse-Per-Second API for UNIX-like Operating Systems, Version 1.0) which in part is implemented by this patch. It provides a set of chars devices, one per PPS source, which can be used to get the time signal. The RFC's functions can be implemented by accessing to these char devices. Signed-off-by: Rodolfo Giometti <giometti@linux.it> --- Documentation/ABI/testing/sysfs-pps | 73 ++++++++ Documentation/ioctl-number.txt | 2 + Documentation/pps/pps.txt | 172 ++++++++++++++++++ MAINTAINERS | 7 + drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/pps/Kconfig | 33 ++++ drivers/pps/Makefile | 8 + drivers/pps/kapi.c | 322 +++++++++++++++++++++++++++++++++ drivers/pps/pps.c | 335 +++++++++++++++++++++++++++++++++++ drivers/pps/sysfs.c | 104 +++++++++++ include/linux/Kbuild | 1 + include/linux/pps.h | 202 +++++++++++++++++++++ 13 files changed, 1262 insertions(+), 0 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-pps create mode 100644 Documentation/pps/pps.txt create mode 100644 drivers/pps/Kconfig create mode 100644 drivers/pps/Makefile create mode 100644 drivers/pps/kapi.c create mode 100644 drivers/pps/pps.c create mode 100644 drivers/pps/sysfs.c create mode 100644 include/linux/pps.h diff --git ...
This patch adds into the PPS's documentation directory a possible
implementation of the PPS API (RFC 2783) by using the LinuxPPS's char
devices.
This file is not just an example but it can be used into real
systems. :)
Signed-off-by: Rodolfo Giometti <giometti@linux.it>
---
Documentation/pps/timepps.h | 195 +++++++++++++++++++++++++++++++++++++++++++
1 files changed, 195 insertions(+), 0 deletions(-)
create mode 100644 Documentation/pps/timepps.h
diff --git a/Documentation/pps/timepps.h b/Documentation/pps/timepps.h
new file mode 100644
index 0000000..2372949
--- /dev/null
+++ b/Documentation/pps/timepps.h
@@ -0,0 +1,195 @@
+/*
+ * timepps.h -- PPS API main header
+ *
+ * Copyright (C) 2005-2007 Rodolfo Giometti <giometti@linux.it>
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _SYS_TIMEPPS_H_
+#define _SYS_TIMEPPS_H_
+
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <errno.h>
+#include <linux/pps.h>
+
+#define LINUXPPS 1 /* signal we are using LinuxPPS */
+
+/*
+ * New data structures
+ */
+
+struct ntp_fp {
+ unsigned int integral;
+ unsigned int fractional;
+};
+
+union pps_timeu {
+ struct timespec tspec;
+ struct ntp_fp ntpfp;
+ unsigned long longpad[3];
+};
+
+struct pps_info {
+ unsigned long assert_sequence; /* seq. num. of ...Here some utilities and examples about the PPS API and the LinuxPPS
support.
* ppsldisc.c shows how to manage PPS line discipline;
* ppstest.c implements an useful testing program, while
* ppsfind tries to help the user into finding a specific PPS source by
using its name or path.
Signed-off-by: Rodolfo Giometti <giometti@linux.it>
---
Documentation/pps/Makefile | 28 ++++++++
Documentation/pps/ppsfind | 17 +++++
Documentation/pps/ppsldisc.c | 46 +++++++++++++
Documentation/pps/ppstest.c | 151 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 242 insertions(+), 0 deletions(-)
create mode 100644 Documentation/pps/Makefile
create mode 100644 Documentation/pps/ppsfind
create mode 100644 Documentation/pps/ppsldisc.c
create mode 100644 Documentation/pps/ppstest.c
diff --git a/Documentation/pps/Makefile b/Documentation/pps/Makefile
new file mode 100644
index 0000000..9841e6b
--- /dev/null
+++ b/Documentation/pps/Makefile
@@ -0,0 +1,28 @@
+TARGETS = ppstest ppsldisc
+
+CFLAGS += -Wall -O2 -D_GNU_SOURCE
+CFLAGS += -I .
+CFLAGS += -ggdb
+CFLAGS += -D__N_PPS=$(shell awk '/N_PPS/ {print $$3}' ../../include/linux/tty.h)
+
+# -- Actions section --
+
+.PHONY : all depend dep
+
+all : .depend $(TARGETS)
+
+.depend depend dep :
+ $(CC) $(CFLAGS) -M $(TARGETS:=.c) > .depend
+
+ifeq (.depend,$(wildcard .depend))
+include .depend
+endif
+
+
+# -- Clean section --
+
+.PHONY : clean
+
+clean :
+ rm -f *.o *~ core .depend
+ rm -f ${TARGETS}
diff --git a/Documentation/pps/ppsfind b/Documentation/pps/ppsfind
new file mode 100644
index 0000000..93c0e17
--- /dev/null
+++ b/Documentation/pps/ppsfind
@@ -0,0 +1,17 @@
+#!/bin/sh
+
+SYS="/sys/class/pps/"
+
+if [ $# -lt 1 ] ; then
+ echo "usage: ppsfind <name>" >&2
+ exit 1
+fi
+
+for d in $(ls $SYS) ; do
+ if grep $1 $SYS/$d/name >& /dev/null || \
+ grep $1 $SYS/$d/path >& /dev/null ; then
+ echo "$d: name=$(cat $SYS/$d/name) path=$(cat $SYS/$d/path)"
+ fi
+done
+
+exit ...Each PPS source can be registered/deregistered into the system by using special modules called "clients". They simply define the PPS sources' attributes and implement the time signal registartion mechanism. This patch adds a special directory for such clients and adds a dummy client that can be useful to test system integrity on real systems. Signed-off-by: Rodolfo Giometti <giometti@linux.it> --- drivers/pps/Kconfig | 2 + drivers/pps/Makefile | 1 + drivers/pps/clients/Kconfig | 18 ++++++ drivers/pps/clients/Makefile | 9 +++ drivers/pps/clients/ktimer.c | 124 ++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 154 insertions(+), 0 deletions(-) create mode 100644 drivers/pps/clients/Kconfig create mode 100644 drivers/pps/clients/Makefile create mode 100644 drivers/pps/clients/ktimer.c diff --git a/drivers/pps/Kconfig b/drivers/pps/Kconfig index cc2eb8e..1afe4e0 100644 --- a/drivers/pps/Kconfig +++ b/drivers/pps/Kconfig @@ -30,4 +30,6 @@ config PPS_DEBUG messages to the system log. Select this if you are having a problem with PPS support and want to see more of what is going on. +source drivers/pps/clients/Kconfig + endmenu diff --git a/drivers/pps/Makefile b/drivers/pps/Makefile index 19ea582..98960dd 100644 --- a/drivers/pps/Makefile +++ b/drivers/pps/Makefile @@ -4,5 +4,6 @@ pps_core-y := pps.o kapi.o sysfs.o obj-$(CONFIG_PPS) := pps_core.o +obj-y += clients/ ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig new file mode 100644 index 0000000..60b83be --- /dev/null +++ b/drivers/pps/clients/Kconfig @@ -0,0 +1,18 @@ +# +# PPS clients configuration +# + +if PPS + +comment "PPS clients support" + +config PPS_CLIENT_KTIMER + tristate "Kernel timer client (Testing client, use for debug)" + help + If you say yes here you get support for a PPS debugging client + which uses a kernel timer to generate the PPS ...
Signed-off-by: Rodolfo Giometti <giometti@linux.it>
---
Documentation/tty.txt | 4 ++++
include/linux/tty_ldisc.h | 8 ++++++++
2 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/Documentation/tty.txt b/Documentation/tty.txt
index 8e65c44..3fc812a 100644
--- a/Documentation/tty.txt
+++ b/Documentation/tty.txt
@@ -100,6 +100,10 @@ write_wakeup() - May be called at any point between open and close.
is permitted to call the driver write method from
this function. In such a situation defer it.
+dcd_change() - Report to the tty line the current DCD pin status
+ changes and the relative timestamp. The timestamp
+ can be NULL.
+
Driver Access
diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index 40f38d8..526fbf4 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -99,6 +99,12 @@
* cease I/O to the tty driver. Can sleep. The driver should
* seek to perform this action quickly but should wait until
* any pending driver I/O is completed.
+ *
+ * void (*dcd_change)(struct tty_struct *tty, unsigned int status,
+ * struct timespec *ts)
+ *
+ * Tells the discipline that the DCD pin has changed its status and
+ * the relative timestamp. Pointer ts can be NULL.
*/
#include <linux/fs.h>
@@ -136,6 +142,8 @@ struct tty_ldisc_ops {
void (*receive_buf)(struct tty_struct *, const unsigned char *cp,
char *fp, int count);
void (*write_wakeup)(struct tty_struct *);
+ void (*dcd_change)(struct tty_struct *, unsigned int,
+ struct timespec *);
struct module *owner;
--
1.5.4.3
--
Signed-off-by: Rodolfo Giometti <giometti@linux.it>
---
drivers/char/n_tty.c | 54 +++++++++++++++++++++++++++++--------------------
include/linux/tty.h | 16 ++++++++++++++
2 files changed, 48 insertions(+), 22 deletions(-)
diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index 708c2b1..8458ded 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -26,7 +26,7 @@
*
* 2002/03/18 Implemented n_tty_wakeup to send SIGIO POLL_OUTs to
* waiting writing processes-Sapan Bhatia <sapan@corewars.org>.
- * Also fixed a bug in BLOCKING mode where write_chan returns
+ * Also fixed a bug in BLOCKING mode where n_tty_write returns
* EAGAIN
*/
@@ -43,10 +43,10 @@
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/slab.h>
-#include <linux/poll.h>
#include <linux/bitops.h>
#include <linux/audit.h>
#include <linux/file.h>
+#include <linux/module.h>
#include <asm/uaccess.h>
#include <asm/system.h>
@@ -184,7 +184,7 @@ static void reset_buffer_flags(struct tty_struct *tty)
* Locking: ctrl_lock
*/
-static void n_tty_flush_buffer(struct tty_struct *tty)
+void n_tty_flush_buffer(struct tty_struct *tty)
{
unsigned long flags;
/* clear everything and unthrottle the driver */
@@ -200,6 +200,7 @@ static void n_tty_flush_buffer(struct tty_struct *tty)
}
spin_unlock_irqrestore(&tty->ctrl_lock, flags);
}
+EXPORT_SYMBOL_GPL(n_tty_flush_buffer);
/**
* n_tty_chars_in_buffer - report available bytes
@@ -209,7 +210,7 @@ static void n_tty_flush_buffer(struct tty_struct *tty)
* at this instant in time.
*/
-static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
+ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
{
unsigned long flags;
ssize_t n = 0;
@@ -225,6 +226,7 @@ static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
spin_unlock_irqrestore(&tty->read_lock, flags);
return n;
}
+EXPORT_SYMBOL_GPL(n_tty_chars_in_buffer);
/**
* is_utf8_continuation - utf8 ...Add a new line discipline for "pulse per second" devices connected to a serial port. Signed-off-by: Rodolfo Giometti <giometti@linux.it> --- include/linux/tty.h | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/include/linux/tty.h b/include/linux/tty.h index 826d695..1857db2 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -24,7 +24,7 @@ */ #define NR_UNIX98_PTY_DEFAULT 4096 /* Default maximum for Unix98 ptys */ #define NR_UNIX98_PTY_MAX (1 << MINORBITS) /* Absolute limit */ -#define NR_LDISCS 18 +#define NR_LDISCS 19 /* line disciplines */ #define N_TTY 0 @@ -46,6 +46,7 @@ #define N_HCI 15 /* Bluetooth HCI UART */ #define N_GIGASET_M101 16 /* Siemens Gigaset M101 serial DECT adapter */ #define N_SLCAN 17 /* Serial / USB serial CAN Adaptors */ +#define N_PPS 18 /* Pulse per Second */ /* * This character is the same as _POSIX_VDISABLE: it cannot be used as -- 1.5.4.3 --
Adds support, by using the PPS line discipline, for the PPS sources connected with the CD (Carrier Detect) pin of a serial port. Signed-off-by: Rodolfo Giometti <giometti@linux.it> --- drivers/pps/clients/Kconfig | 7 ++ drivers/pps/clients/Makefile | 1 + drivers/pps/clients/pps-ldisc.c | 154 +++++++++++++++++++++++++++++++++++++++ drivers/serial/8250.c | 13 +++ include/linux/serial_core.h | 10 ++- 5 files changed, 184 insertions(+), 1 deletions(-) create mode 100644 drivers/pps/clients/pps-ldisc.c diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig index 60b83be..487c1c8 100644 --- a/drivers/pps/clients/Kconfig +++ b/drivers/pps/clients/Kconfig @@ -15,4 +15,11 @@ config PPS_CLIENT_KTIMER This driver can also be built as a module. If so, the module will be called ktimer.ko. +config PPS_CLIENT_LDISC + tristate "PPS line discipline" + depends on PPS + help + If you say yes here you get support for a PPS source connected + with the CD (Carrier Detect) pin of your serial port. + endif diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile index f3c1e39..9f5b988 100644 --- a/drivers/pps/clients/Makefile +++ b/drivers/pps/clients/Makefile @@ -3,6 +3,7 @@ # obj-$(CONFIG_PPS_CLIENT_KTIMER) += ktimer.o +obj-$(CONFIG_PPS_CLIENT_LDISC) += pps-ldisc.o ifeq ($(CONFIG_PPS_DEBUG),y) EXTRA_CFLAGS += -DDEBUG diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c new file mode 100644 index 0000000..6484f17 --- /dev/null +++ b/drivers/pps/clients/pps-ldisc.c @@ -0,0 +1,154 @@ +/* + * pps-ldisc.c -- PPS line discipline + * + * + * Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it> + * + * 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. + ...
Adds support for the PPS sources connected with the interrupt pin of a
parallel port.
Signed-off-by: Rodolfo Giometti <giometti@linux.it>
---
drivers/char/lp.c | 61 +++++++++++++++++++++++++++++++++++++++++++
drivers/pps/clients/Kconfig | 10 +++++++
include/linux/parport.h | 22 +++++++++++++++
3 files changed, 93 insertions(+), 0 deletions(-)
diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index 3f2719b..84e0bb0 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -760,6 +760,27 @@ static struct console lpcons = {
#endif /* console on line printer */
+/* Support for PPS signal on the line printer */
+
+#ifdef CONFIG_PPS_CLIENT_LP
+
+static void lp_pps_echo(int source, int event, void *data)
+{
+ struct parport *port = data;
+ unsigned char status = parport_read_status(port);
+
+ /* echo event via SEL bit */
+ parport_write_control(port,
+ parport_read_control(port) | PARPORT_CONTROL_SELECT);
+
+ /* signal no event */
+ if ((status & PARPORT_STATUS_ACK) != 0)
+ parport_write_control(port,
+ parport_read_control(port) & ~PARPORT_CONTROL_SELECT);
+}
+
+#endif
+
/* --- initialisation code ------------------------------------- */
static int parport_nr[LP_NO] = { [0 ... LP_NO-1] = LP_PARPORT_UNSPEC };
@@ -831,6 +852,38 @@ static int lp_register(int nr, struct parport *port)
}
#endif
+#ifdef CONFIG_PPS_CLIENT_LP
+ port->pps_info.owner = THIS_MODULE;
+ port->pps_info.dev = port->dev;
+ snprintf(port->pps_info.path, PPS_MAX_NAME_LEN, "/dev/lp%d", nr);
+
+ /* No PPS support if lp port has no IRQ line */
+ if (port->irq != PARPORT_IRQ_NONE) {
+ strncpy(port->pps_info.name, port->name, PPS_MAX_NAME_LEN);
+
+ port->pps_info.mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT | \
+ PPS_ECHOASSERT | \
+ PPS_CANWAIT | PPS_TSFMT_TSPEC;
+
+ port->pps_info.echo = lp_pps_echo;
+
+ port->pps_source = pps_register_source(&(port->pps_info),
+ PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
+ if (port->pps_source < ...Add low level IRQ timestamps recording for x86 (32 and 64 bits)
platforms and enable UART clients in order to use it.
This improves PPS precision. :)
Signed-off-by: Rodolfo Giometti <giometti@linux.it>
---
arch/x86/kernel/irq_32.c | 17 +++++++++++++++++
arch/x86/kernel/irq_64.c | 21 +++++++++++++++++++--
drivers/pps/Kconfig | 12 ++++++++++++
include/linux/pps.h | 1 +
include/linux/serial_core.h | 7 ++++++-
5 files changed, 55 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index 1cf8c1f..85c3182 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -15,6 +15,7 @@
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/delay.h>
+#include <linux/pps.h>
#include <asm/apic.h>
#include <asm/uaccess.h>
@@ -25,6 +26,11 @@ EXPORT_PER_CPU_SYMBOL(irq_stat);
DEFINE_PER_CPU(struct pt_regs *, irq_regs);
EXPORT_PER_CPU_SYMBOL(irq_regs);
+#ifdef CONFIG_PPS_IRQ_EVENTS
+struct timespec pps_irq_ts[NR_IRQS];
+EXPORT_SYMBOL(pps_irq_ts);
+#endif
+
/*
* 'what should we do if we get a hw irq event on an illegal vector'.
* each architecture has to answer this themselves.
@@ -225,6 +231,12 @@ unsigned int do_IRQ(struct pt_regs *regs)
/* high bit used in ret_from_ code */
int overflow, irq = ~regs->orig_ax;
struct irq_desc *desc = irq_desc + irq;
+#ifdef CONFIG_PPS_IRQ_EVENTS
+ struct timespec ts;
+
+ /* Get IRQ timestamps as soon as possible for the PPS layer */
+ getnstimeofday(&ts);
+#endif
if (unlikely((unsigned)irq >= NR_IRQS)) {
printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
@@ -232,6 +244,11 @@ unsigned int do_IRQ(struct pt_regs *regs)
BUG();
}
+#ifdef CONFIG_PPS_IRQ_EVENTS
+ /* Then, after sanity check, store the IRQ timestamp */
+ pps_irq_ts[irq] = ts;
+#endif
+
old_regs = set_irq_regs(regs);
irq_enter();
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 1f78b23..e9184ce 100644
--- ...Hey Rodolfo, First of all, kudos to your persistence on this patch set, it really has been a long time that you've been pushing this. Hopefully it won't take much longer. :) I've never had much experience with PPS devices, so other then knowing a fair number of folks who are interested in using them, most of the code is outside of my realm of knowledge, so I've not had much to comment upon. However, Thomas asked me to check and see how this interacted with the timekeeping subsystem, so I took another look at the current code. From a quick review, I really don't see any interactions. The code seems fairly well isolated. One question I have is: Do you have any plans for integrating with the adjtimex() interface and its pps values? My only other comment is on this last patch #10, and as you said in your original post, its deferrable. I'd agree that dropping this patch for now would be best, since adding a getnstimeofday() call, which may take a few microseconds on common hardware, to every interrupt would be a bad idea. It seems having a special flag on the IRQ for timestamping would be better, and then we could only enable it for PPS connected interrupts. It may add a touch more jitter but I think it would allow for better performance while still reducing jitter. So yea. Unless there are objections from the serial and parallel port maintainers, or someone who has more experience with PPS devices and might better critique the API proposed, I see no reason for holding this patch set back from my (limited) perspective. thanks -john --
I see... neither if we disable it by default in the configuration menu and we remark in the help message that it could be dangerous? :P However if that patch is blocking for the others then I prefere It sounds good! But do you already have any idea about how to do it? It's not an easy task since some drivers may not know at all that they are managing a PPS device! As example, think about serial PPS devices, they are managed by proper line discipline, so how can we modify the Thanks a lot for your time! I hope Linux may have this API support soon! :) Ciao, Rodolfo -- GNU/Linux Solutions e-mail: giometti@enneenne.com Linux Device Driver giometti@linux.it Embedded Systems phone: +39 349 2432127 UNIX programming skype: rodolfo.giometti --
Why limit this to just DCD change, and not any of the other status bits (DCD, RI, DSR, CTS)? -hpa --
On Thu, 02 Oct 2008 08:25:57 -0700 We can change that later if anyone wants the other bits. I'm quite happy with that side of it, the real question is the core code. The tty bits can then get a spit and polish in the ttydev tree. Alan --
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