Hi pekka I'm not familiar with kernel. I know part of drm driver is implement by ourself. I check the vblank callback function, it sends pageflip event first if there is a frame complete, update vblank timestamp later.
I don't know why the owner write code like this. but if I swap the code order, the fps decrease a lot. I can sure this impact the weston's page flip timestamp. Does this have some impacts to weston except timeline? I study a little about timeline, I think the picture could still show the c2p(interval between damage commit and hit screen). Is it right? Thank you. Best Regards Nancy 2018-05-24 15:42 GMT+08:00 Pekka Paalanen <ppaala...@gmail.com>: > On Thu, 24 May 2018 15:26:23 +0800 > zou lan <nancy.lan....@gmail.com> wrote: > > > Hi pekka > > > > >>are the c2p numbers from weston-presentation-shm demo? > > yes. I use this demo. My clock is CLOCK_MONOTONIC. > > > > I check the drm kernel code, I find each vblank event send the last > > vblank's timestamp. > > > > system time sec msec > > [ 263.000526] vblank_event 262 983 > > [ 263.017236] vblank_event 263 0 > > [ 263.033864] vblank_event 263 17 > > [ 263.050533] vblank_event 263 33 > > [ 263.067215] vblank_event 263 50 > > > > I think that's should be the main reason cause the c2p time weird. I > don't > > know why kernel return last frame's timestamp. I am still debuging it. > > Indeed, that does not sound right. Maybe contact the driver developers > about this? > > Which kernel display driver are you using? > > > Thanks, > pq >
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