Messages in this thread | | | Subject | Re: old radeon latency problem still unfixed? | From | Benjamin Herrenschmidt <> | Date | Mon, 27 Feb 2006 09:53:46 +1100 |
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On Sun, 2006-02-26 at 16:31 -0500, Lee Revell wrote: > On Mon, 2006-02-27 at 08:11 +1100, Benjamin Herrenschmidt wrote: > > > AFAICT it's more like trading 3D performance for having audio work at > > > all. Other video drivers that were too aggressive and caused audio > > > dropouts (VIA) were fixed, even though there was a slight performance > > > cost. > > > > In addition, the radeon DRI shouldn't do active spinning like that in > > "normal" circumstances ... it should instead block on interrupts. if it > > does, I suppose that could safely be considered as a bug in the radeon > > DRM/DRI driver. It will do such loops on engine reset and such, which > > happen on X launch, VT switches or in case of lockups... I have to > > double check what happens in the code path used for 2d/3d transitions > > though, those might be a problem. > > What about switching from 2D->3D mode, like when xscreensaver kicks in? > IIRC people reported audio underruns when that happened but I could > never narrow it down any further.
Well... as soon as a 3d window appears, the server starts switching all the time. there might be some spin loop in there remaining...
> If as Arjan said the only lock this driver takes is the BKL then it's > either a local config issue (ancient kernel or failure to enable preempt > BKL) or something at the hardware level... I'm waiting for more info > from the original reporter.
Ben.
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