pps: Move timestamp read into PPS code proper

The PPS (Pulse-Per-Second) line discipline has developed a number of
unhealthy attachments to core tty data and functions, ultimately leading
to its breakage.

The previous patches fixed the crashing.  This one reduces coupling further
by eliminating the timestamp parameter from the dcd_change ldisc method.
This reduces header file linkage and makes the extension more generic,
and the timestamp read is delayed only slightly, from just before the
ldisc->ops->dcd_change method call to just after.

Fix attendant build breakage in
    drivers/tty/n_tty.c
    drivers/tty/tty_buffer.c
    drivers/staging/speakup/selection.c
    drivers/staging/dgrp/dgrp_*.c

Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@braille.uwo.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: George Spelvin <linux@horizon.com>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c
index a94f73e1480d0e5b3c45eee167fdc95a3f1303c2..73bd3bb4d93b5945c89b49a7ed60ea49750da796 100644 (file)
--- a/drivers/pps/clients/pps-ldisc.c
+++ b/drivers/pps/clients/pps-ldisc.c
@@ -29,11 +29,14 @@
 
 #define PPS_TTY_MAGIC          0x0001
 
-static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status,
-                               struct pps_event_time *ts)
+static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status)
 {
-       struct pps_device *pps = pps_lookup_dev(tty);
+       struct pps_device *pps;
+       struct pps_event_time ts;
+
+       pps_get_ts(&ts);
 
+       pps = pps_lookup_dev(tty);
        /*
         * This should never fail, but the ldisc locking is very
         * convoluted, so don't crash just in case.
@@ -42,7 +45,7 @@ static void pps_tty_dcd_change(struct tty_struct *tty, unsigned int status,
                return;
 
        /* Now do the PPS event report */
-       pps_event(pps, ts, status ? PPS_CAPTUREASSERT :
+       pps_event(pps, &ts, status ? PPS_CAPTUREASSERT :
                        PPS_CAPTURECLEAR, NULL);
 
        dev_dbg(pps->dev, "PPS %s at %lu\n",

diff --git a/drivers/staging/dgrp/dgrp_net_ops.c b/drivers/staging/dgrp/dgrp_net_ops.c
index 4c7abfabf19783a573896949df2e6b408eb3e3ab..e6018823b9deca9079ff3ee72251a5669ad99b2f 100644 (file)
--- a/drivers/staging/dgrp/dgrp_net_ops.c
+++ b/drivers/staging/dgrp/dgrp_net_ops.c
@@ -37,6 +37,7 @@
 #include <linux/proc_fs.h>
 #include <linux/types.h>
 #include <linux/string.h>
+#include <linux/device.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
 #include <linux/spinlock.h>

diff --git a/drivers/staging/dgrp/dgrp_tty.c b/drivers/staging/dgrp/dgrp_tty.c
index 51d3ed3dca277e2d0cb1cf5d63a19711d996d6a2..654f6010b473d7d93e817bf58cf7b9c4a2e0bd58 100644 (file)
--- a/drivers/staging/dgrp/dgrp_tty.c
+++ b/drivers/staging/dgrp/dgrp_tty.c
@@ -39,6 +39,7 @@
 #include <linux/slab.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
+#include <linux/device.h>
 #include <linux/sched.h>
 #include <linux/uaccess.h>
 

diff --git a/drivers/staging/speakup/selection.c b/drivers/staging/speakup/selection.c
index 0612df06a4bfd08d05499539d5adaa24853a51ad..2aa22379fda001721e3fd5f57e755b08e5b34771 100644 (file)
--- a/drivers/staging/speakup/selection.c
+++ b/drivers/staging/speakup/selection.c
@@ -2,6 +2,7 @@
 #include <linux/consolemap.h>
 #include <linux/interrupt.h>
 #include <linux/sched.h>
+#include <linux/device.h> /* for dev_warn */
 #include <linux/selection.h>
 
 #include "speakup.h"

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 095072899b5edea12eee71da689367cce048e234..05e72bea9b07d87e31c69e291844428cb642d4be 100644 (file)
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -49,6 +49,7 @@
 #include <linux/file.h>
 #include <linux/uaccess.h>
 #include <linux/module.h>
+#include <linux/ratelimit.h>
 
 
 /* number of characters left in xmit buffer before select has we have room */
@@ -2188,7 +2189,7 @@ struct tty_ldisc_ops tty_ldisc_N_TTY = {
  *     n_tty_inherit_ops       -       inherit N_TTY methods
  *     @ops: struct tty_ldisc_ops where to save N_TTY methods
  *
- *     Used by a generic struct tty_ldisc_ops to easily inherit N_TTY
+ *     Enables a 'subclass' line discipline to 'inherit' N_TTY
  *     methods.
  */
 

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index ca98a3f65fe1ffc77a8a26f886ffec1aa51e02c7..765be520cd2e57b672145485a0e4d21b5ac1f215 100644 (file)
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2726,13 +2726,12 @@ 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 = NULL;
-       struct pps_event_time ts;
        struct tty_struct *tty = port->tty;
 
        if (tty)
                ld = tty_ldisc_ref(tty);
        if (ld && ld->ops->dcd_change)
-               pps_get_ts(&ts);
+               ld->ops->dcd_change(tty, status);
 
        uport->icount.dcd++;
 #ifdef CONFIG_HARD_PPS
@@ -2747,8 +2746,6 @@ void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
                        tty_hangup(tty);
        }
 
-       if (ld && ld->ops->dcd_change)
-               ld->ops->dcd_change(tty, status, &ts);
        if (ld)
                tty_ldisc_deref(ld);
 }

diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 61ec4ddf47e07f7d079e47c1a9f854a623198168..bb119934e76cd8c70bdde28038553b60867b3282 100644 (file)
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -16,6 +16,7 @@
 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <linux/module.h>
+#include <linux/ratelimit.h>
 
 /**
  *     tty_buffer_free_all             -       free buffers used by a tty

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index d97142159e0f0765a87de2b30d764c0b72228da3..87d4bbc773fc7d8d7223423c9d388accc32c527c 100644 (file)
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -29,7 +29,6 @@
 #include <linux/tty.h>
 #include <linux/mutex.h>
 #include <linux/sysrq.h>
-#include <linux/pps_kernel.h>
 #include <uapi/linux/serial_core.h>
 
 struct uart_port;

diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index fb79dd8d1537fd5e5ed06ac0ec813421e1298975..455a0d7bf2209665adc5c09bb8f4c2803edc3f49 100644 (file)
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -100,16 +100,14 @@
  *     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 pps_event_time *ts)
+ * void (*dcd_change)(struct tty_struct *tty, unsigned int status)
  *
- *     Tells the discipline that the DCD pin has changed its status and
- *     the relative timestamp. Pointer ts cannot be NULL.
+ *     Tells the discipline that the DCD pin has changed its status.
+ *     Used exclusively by the N_PPS (Pulse-Per-Second) line discipline.
  */
 
 #include <linux/fs.h>
 #include <linux/wait.h>
-#include <linux/pps_kernel.h>
 #include <linux/wait.h>
 
 struct tty_ldisc_ops {
@@ -144,8 +142,7 @@ 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 pps_event_time *);
+       void    (*dcd_change)(struct tty_struct *, unsigned int);
 
        struct  module *owner;