Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer and time updates from Thomas Gleixner:
 "A rather large update of timers, timekeeping & co

   - Core timekeeping code is year-2038 safe now for 32bit machines.
     Now we just need to fix all in kernel users and the gazillion of
     user space interfaces which rely on timespec/timeval :)

   - Better cache layout for the timekeeping internal data structures.

   - Proper nanosecond based interfaces for in kernel users.

   - Tree wide cleanup of code which wants nanoseconds but does hoops
     and loops to convert back and forth from timespecs.  Some of it
     definitely belongs into the ugly code museum.

   - Consolidation of the timekeeping interface zoo.

   - A fast NMI safe accessor to clock monotonic for tracing.  This is a
     long standing request to support correlated user/kernel space
     traces.  With proper NTP frequency correction it's also suitable
     for correlation of traces accross separate machines.

   - Checkpoint/restart support for timerfd.

   - A few NOHZ[_FULL] improvements in the [hr]timer code.

   - Code move from kernel to kernel/time of all time* related code.

   - New clocksource/event drivers from the ARM universe.  I'm really
     impressed that despite an architected timer in the newer chips SoC
     manufacturers insist on inventing new and differently broken SoC
     specific timers.

[ Ed. "Impressed"? I don't think that word means what you think it means ]

   - Another round of code move from arch to drivers.  Looks like most
     of the legacy mess in ARM regarding timers is sorted out except for
     a few obnoxious strongholds.

   - The usual updates and fixlets all over the place"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (114 commits)
  timekeeping: Fixup typo in update_vsyscall_old definition
  clocksource: document some basic timekeeping concepts
  timekeeping: Use cached ntp_tick_length when accumulating error
  timekeeping: Rework frequency adjustments to work better w/ nohz
  timekeeping: Minor fixup for timespec64->timespec assignment
  ftrace: Provide trace clocks monotonic
  timekeeping: Provide fast and NMI safe access to CLOCK_MONOTONIC
  seqcount: Add raw_write_seqcount_latch()
  seqcount: Provide raw_read_seqcount()
  timekeeping: Use tk_read_base as argument for timekeeping_get_ns()
  timekeeping: Create struct tk_read_base and use it in struct timekeeper
  timekeeping: Restructure the timekeeper some more
  clocksource: Get rid of cycle_last
  clocksource: Move cycle_last validation to core code
  clocksource: Make delta calculation a function
  wireless: ath9k: Get rid of timespec conversions
  drm: vmwgfx: Use nsec based interfaces
  drm: i915: Use nsec based interfaces
  timekeeping: Provide ktime_get_raw()
  hangcheck-timer: Use ktime_get_ns()
  ...

1 files changed, 3 insertions, 13 deletions

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 0de123afdb34..08ba1209228e 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -542,8 +542,8 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
 					  const struct drm_crtc *refcrtc,
 					  const struct drm_display_mode *mode)
 {
-	ktime_t stime, etime, mono_time_offset;
 	struct timeval tv_etime;
+	ktime_t stime, etime;
 	int vbl_status;
 	int vpos, hpos, i;
 	int framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
@@ -588,13 +588,6 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
 		vbl_status = dev->driver->get_scanout_position(dev, crtc, flags, &vpos,
 							       &hpos, &stime, &etime);
 
-		/*
-		 * Get correction for CLOCK_MONOTONIC -> CLOCK_REALTIME if
-		 * CLOCK_REALTIME is requested.
-		 */
-		if (!drm_timestamp_monotonic)
-			mono_time_offset = ktime_get_monotonic_offset();
-
 		/* Return as no-op if scanout query unsupported or failed. */
 		if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
 			DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
@@ -633,7 +626,7 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
 	delta_ns = vpos * linedur_ns + hpos * pixeldur_ns;
 
 	if (!drm_timestamp_monotonic)
-		etime = ktime_sub(etime, mono_time_offset);
+		etime = ktime_mono_to_real(etime);
 
 	/* save this only for debugging purposes */
 	tv_etime = ktime_to_timeval(etime);
@@ -664,10 +657,7 @@ static struct timeval get_drm_timestamp(void)
 {
 	ktime_t now;
 
-	now = ktime_get();
-	if (!drm_timestamp_monotonic)
-		now = ktime_sub(now, ktime_get_monotonic_offset());
-
+	now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
 	return ktime_to_timeval(now);
 }