Re: [PATCH] [RESEND] vmwgfx: use monotonic event timestamps

[Woody Suwalski]

Thomas Hellstrom wrote:
> Hi, Arnd,
>
> Sinclair's on paternal leave and I thought this patch was already in 
> drm-next. My bad.
> Dave, is it too late to pull this in for the next merge window?
>
> /Thomas
>
>
> On 01/16/2018 06:18 PM, Arnd Bergmann wrote:
> > 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().
> >
> > Link: 
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__patchwork.kernel.org_patch_10076599_&d=DwIBAg&c=uilaK90D4TOVoH58JNXRgQ&r=wnSlgOCqfpNS4d02vP68_E9q2BNMCwfD2OZ_6dCFVQQ&m=8M6vawBo0zDsjbqhzV0xpOwAzX7Zm-uyGlIDnQ7-Gms&s=sHGuz0aoE9aLjVp5GALo8mYrN1bwOHW6mGpJIZmhwAc&e=
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > ---
> > Originally sent on Nov 27. Sinclair Yeh said he'd pick it up
> > for the next pull request, but it's not in linux-next yet.
> >
> > Resending the unchanged patch, please pick it up when you have time,
> > or feel free to ignore this email in case it's already in some tree
> > that just isn't part of linux-next but will be sent during the
> > next merge window.
> > ---
> > Â drivers/gpu/drm/vmwgfx/vmwgfx_fence.c | 9 +++++----
> > Â 1 file changed, 5 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c 
> > b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
> > index 6c5c75cf5e6c..9ed544f8958f 100644
> > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
> > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
> > @@ -901,11 +901,12 @@ static void 
> > vmw_event_fence_action_seq_passed(struct vmw_fence_action *action)
> > ÂÂÂÂÂ spin_lock_irq(&dev->event_lock);
> > Â ÂÂÂÂÂ if (likely(eaction->tv_sec != NULL)) {
> > -ÂÂÂÂÂÂÂ struct timeval tv;
> > +ÂÂÂÂÂÂÂ struct timespec64 ts;
> > Â -ÂÂÂÂÂÂÂ do_gettimeofday(&tv);
> > -ÂÂÂÂÂÂÂ *eaction->tv_sec = tv.tv_sec;
> > -ÂÂÂÂÂÂÂ *eaction->tv_usec = tv.tv_usec;
> > +ÂÂÂÂÂÂÂ ktime_get_ts64(&ts);
> > +ÂÂÂÂÂÂÂ /* monotonic time, so no y2038 overflow */
> > +ÂÂÂÂÂÂÂ *eaction->tv_sec = ts.tv_sec;
> > +ÂÂÂÂÂÂÂ *eaction->tv_usec = ts.tv_nsec / NSEC_PER_USEC;
> > ÂÂÂÂÂ }
> > Â ÂÂÂÂÂ drm_send_event_locked(dev, eaction->event);
Thomas, the same way my DRM patch has disappeared:
Date

	Tue, 19 Dec 2017 11:50:57 -0800
> From 	Sinclair Yeh <>
Subject 	Re: [PATCH v.2] 4.15 vmgfx boot warning


	

This looks okay to me.

On Mon, Dec 18, 2017 at 07:26:03PM -0500, Woody Suwalski wrote:
> The 4.15 drm_atomic_helper driver shows a warning during boot (both 32 and
> 64 bit x86)
> It is caused by a mismatch between the result of vmw_enable_vblank() and
> what the drm_atomic_helper expects:
> ÂÂ /...
> ÂÂ ret = drm_crtc_vblank_get(crtc);
> ÂÂ WARN_ONCE(ret != -EINVAL, "driver forgot to call
> drm_crtc_vblank_off()\n");
> ÂÂ /...
>
> Signed-off by: Woody Suwalski <terraluna977@xxxxxxxxx>
>
> --- a/drivers/gpu/drm/drm_atomic_helper.cÂÂÂ 2017-12-16 09:55:33.853374561
> -0500
> +++ b/drivers/gpu/drm/drm_atomic_helper.cÂÂÂ 2017-12-16 10:55:56.089090752
> -0500
> @@ -889,7 +889,7 @@ disable_outputs(struct drm_device *dev,
> ÂÂÂÂ ÂÂÂ ÂÂÂ continue;
>
> ÂÂÂÂ ÂÂÂ ret = drm_crtc_vblank_get(crtc);
> -ÂÂÂ ÂÂÂ WARN_ONCE(ret != -EINVAL, "driver forgot to call
> drm_crtc_vblank_off()\n");
> +ÂÂÂ ÂÂÂ WARN_ONCE((ret != -EINVAL && ret != -ENOSYS), "driver forgot to
> call drm_crtc_vblank_off()\n");
> ÂÂÂÂ ÂÂÂ if (ret == 0)
> ÂÂÂÂ ÂÂÂ ÂÂÂ drm_crtc_vblank_put(crtc);
> ÂÂÂÂ }

===============================================

The 4.15 drm_atomic_helper driver shows a warning during boot.
It is caused by a mismatch between the result of vmw_enable_vblank() and
what the drm_atomic_helper expects:
  Â /...
 ÂÂ ret = drm_crtc_vblank_get(crtc);
 ÂÂ WARN_ONCE(ret != -EINVAL, "driver forgot to call drm_crtc_vblank_off()\n");
 ÂÂ /...

Signed-off by: Woody Suwalski <terraluna977@xxxxxxxxx>

--- a/drivers/gpu/drm/drm_atomic_helper.c	2017-12-16 09:55:33.853374561 -0500
+++ b/drivers/gpu/drm/drm_atomic_helper.c	2017-12-16 10:55:56.089090752 -0500
@@ -889,7 +889,7 @@ disable_outputs(struct drm_device *dev,
 			continue;
 
 		ret = drm_crtc_vblank_get(crtc);
-		WARN_ONCE(ret != -EINVAL, "driver forgot to call drm_crtc_vblank_off()\n");
+		WARN_ONCE((ret != -EINVAL && ret != -ENOSYS), "driver forgot to call drm_crtc_vblank_off()\n");
 		if (ret == 0)
 			drm_crtc_vblank_put(crtc);
 	}