drm/vmwgfx: use monotonic event timestamps

BugLink: https://launchpad.net/bugs/1832138
DRM_VMW_EVENT_FENCE_SIGNALED (struct drm_vmw_event_fence) and
DRM_EVENT_VBLANK (struct drm_event_vblank) pass timestamps in 32-bit
seconds/microseconds format.

As of commit c61eef726a78 ("drm: add support for monotonic vblank
timestamps"), other DRM drivers use monotonic times for drm_event_vblank,
but vmwgfx still uses CLOCK_REALTIME for both events, which suffers from
the y2038/y2106 overflow as well as time jumps.

For consistency, this changes vmwgfx to use ktime_get_ts64 as well,
which solves those problems and avoids the deprecated do_gettimeofday()
function.

This should be transparent to to user space, as long as it doesn't
compare the time against the result of gettimeofday().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
(cherry picked from commit 37efe80ce85f76b3b30d7b4ea40550e6a5a5b71a)
Signed-off-by: Eric Desrochers <eric.desrochers@canonical.com>
Signed-off-by: Daniel van Vugt <daniel.van.vugt@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
index d6b1c509ae019d1aae404ff5163506d5e819155e..55214d0da66e83e602ab356d06da52689da903f6 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
@@ -897,11 +897,12 @@ static void vmw_event_fence_action_seq_passed(struct vmw_fence_action *action)
        spin_lock_irq(&dev->event_lock);
 
        if (likely(eaction->tv_sec != NULL)) {
-               struct timeval tv;
+               struct timespec64 ts;
 
-               do_gettimeofday(&tv);
-               *eaction->tv_sec = tv.tv_sec;
-               *eaction->tv_usec = tv.tv_usec;
+               ktime_get_ts64(&ts);
+               /* monotonic time, so no y2038 overflow */
+               *eaction->tv_sec = ts.tv_sec;
+               *eaction->tv_usec = ts.tv_nsec / NSEC_PER_USEC;
        }
 
        drm_send_event_locked(dev, eaction->event);