From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH] drm/vkms: Solve bug on kms_crc_cursor tests Date: Thu, 28 Feb 2019 11:11:07 +0100 Message-ID: <20190228101107.GL2665@phenom.ffwll.local> References: <20190225142606.gov32asdq3qe375q@smtp.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190225142606.gov32asdq3qe375q@smtp.gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Shayenne Moura Cc: Rodrigo Siqueira , Haneen Mohammed , Daniel Vetter , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org List-Id: dri-devel@lists.freedesktop.org On Mon, Feb 25, 2019 at 11:26:06AM -0300, Shayenne Moura wrote: > vkms_crc_work_handle needs the value of the actual frame to > schedule the workqueue that calls periodically the vblank > handler and the destroy state functions. However, the frame > value returned from vkms_vblank_simulate is updated and > diminished in vblank_get_timestamp because it is not in a > vblank interrupt, and return an inaccurate value. > > Solve this getting the actual vblank frame directly from the > vblank->count inside the `struct drm_crtc`, instead of using > the `drm_accurate_vblank_count` function. > > Signed-off-by: Shayenne Moura Sorry for the delay, I'm a bit swamped right now :-/ Debug work you're doing here is really impressive! But I have no idea what's going on. It doesn't look like it's just papering over a bug (like the in_vblank_irq check we've discussed on irc), but I also have no idea why it works. I'll pull in Ville, he understands this better than me. -Daniel > --- > drivers/gpu/drm/vkms/vkms_crc.c | 4 +++- > drivers/gpu/drm/vkms/vkms_crtc.c | 4 +++- > 2 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/vkms/vkms_crc.c b/drivers/gpu/drm/vkms/vkms_crc.c > index d7b409a3c0f8..09a8b00ef1f1 100644 > --- a/drivers/gpu/drm/vkms/vkms_crc.c > +++ b/drivers/gpu/drm/vkms/vkms_crc.c > @@ -161,6 +161,8 @@ void vkms_crc_work_handle(struct work_struct *work) > struct vkms_output *out = drm_crtc_to_vkms_output(crtc); > struct vkms_device *vdev = container_of(out, struct vkms_device, > output); > + unsigned int pipe = drm_crtc_index(crtc); > + struct drm_vblank_crtc *vblank = &crtc->dev->vblank[pipe]; > struct vkms_crc_data *primary_crc = NULL; > struct vkms_crc_data *cursor_crc = NULL; > struct drm_plane *plane; > @@ -196,7 +198,7 @@ void vkms_crc_work_handle(struct work_struct *work) > if (primary_crc) > crc32 = _vkms_get_crc(primary_crc, cursor_crc); > > - frame_end = drm_crtc_accurate_vblank_count(crtc); > + frame_end = vblank->count; > > /* queue_work can fail to schedule crc_work; add crc for > * missing frames > diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c > index 8a9aeb0a9ea8..9bf3268e2e92 100644 > --- a/drivers/gpu/drm/vkms/vkms_crtc.c > +++ b/drivers/gpu/drm/vkms/vkms_crtc.c > @@ -10,6 +10,8 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) > vblank_hrtimer); > struct drm_crtc *crtc = &output->crtc; > struct vkms_crtc_state *state = to_vkms_crtc_state(crtc->state); > + unsigned int pipe = drm_crtc_index(crtc); > + struct drm_vblank_crtc *vblank = &crtc->dev->vblank[pipe]; > u64 ret_overrun; > bool ret; > > @@ -20,7 +22,7 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) > DRM_ERROR("vkms failure on handling vblank"); > > if (state && output->crc_enabled) { > - u64 frame = drm_crtc_accurate_vblank_count(crtc); > + u64 frame = vblank->count; > > /* update frame_start only if a queued vkms_crc_work_handle() > * has read the data > -- > 2.17.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch