Hi,
On 11-09-18 01:08, Steve Longerbeam wrote:
Hi Hans,
On 09/10/2018 11:30 AM, Hans de Goede wrote:
Commit 2408898e3b6c ("staging: vboxvideo: Add page-flip support") only calls vbox_crtc_do_set_base() on page-flips, but despite that function's name it only pins the new fb, unpins the old fb and sets vbox_crtc->fb_offset. It does not program the hardware to scan out at the new vbox_crtc->fb_offset value.
Has that always been the case of vbox_crtc_do_set_base()? Or was there a recent commit that changed that behavior?
I believe that always was the case.
I tested this patch using a Weston EGL mock navigation test app around 4.14 time-frame, that exercises page flip and it was scanning out the new fb, but maybe what I was looking at was a scan-out of an old/now stale fb from a previous page-flip.
Yes I think that is what you saw, this was not easy to notice, I noticed that when typing slowly my letters would always appear 2 at a time, then I deliberately typed: 'a' waited a couple of seconds and the 'a' would not show up until I also typed 'b' and then both showed up at once.
This was with GNOME3 as Wayland compositor, which I believe stops sending new frames when nothing changes which makes this very noticeable :)
In any case thanks for fixing.
You are welcome.
Regards,
Hans
Steve
This was causing only every other frame (assuming page-flipping between 2 buffers) to be shown since we kept scanning out of the old (now unpinned!) buffer.
This commit fixes this by adding code to vbox_crtc_page_flip() to tell the hardware to scanout from the new fb_offset.
Fixes: 2408898e3b6c ("staging: vboxvideo: Add page-flip support") Cc: Steve Longerbeam steve_longerbeam@mentor.com Signed-off-by: Hans de Goede hdegoede@redhat.com
drivers/staging/vboxvideo/vbox_mode.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/staging/vboxvideo/vbox_mode.c b/drivers/staging/vboxvideo/vbox_mode.c index a83eac8668d0..79836c8fb909 100644 --- a/drivers/staging/vboxvideo/vbox_mode.c +++ b/drivers/staging/vboxvideo/vbox_mode.c @@ -323,6 +323,11 @@ static int vbox_crtc_page_flip(struct drm_crtc *crtc, if (rc) return rc; + mutex_lock(&vbox->hw_mutex); + vbox_set_view(crtc); + vbox_do_modeset(crtc, &crtc->mode); + mutex_unlock(&vbox->hw_mutex);
spin_lock_irqsave(&drm->event_lock, flags); if (event)