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>

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/pps/clients/pps-ldisc.c b/drivers/pps/clients/pps-ldisc.c
index a94f73e1480d..73bd3bb4d93b 100644
--- 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",