On Fri, Sep 20, 2013 at 12:18:29PM -0300, Paulo Zanoni wrote: > 2013/9/20 Daniel Vetter <daniel@xxxxxxxx>: > > On Thu, Sep 19, 2013 at 09:24:33PM +0100, Chris Wilson wrote: > >> On Thu, Sep 19, 2013 at 05:03:06PM -0300, Paulo Zanoni wrote: > >> > From: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> > >> > > >> > At the end of haswell_crtc_enable we have an intel_wait_for_vblank > >> > with a big comment, and the message suggests it's a workaround for > >> > something we don't really understand. So I removed that wait and > >> > started getting HW state readout error messages saying that the IPS > >> > state is not what we expected. > >> > > >> > I investigated and concluded that after you write IPS_ENABLE to > >> > IPS_CTL, the bit will only actually become 1 on the next vblank. So > >> > add code to wait for the IPS_ENABLE bit. We don't really need this > >> > wait right now due to the wait I already mentioned, but at least this > >> > one has a reason to be there, while the other one is just to > >> > workaround some problem: we may remove it in the future. > >> > > >> > The wait also acts as a POSTING_READ which we missed. > >> > > >> > Signed-off-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> > >> > >> Both patches: > >> Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > >> > >> I was thinking that maybe the intel_wait_for_vblank would be better from > >> a documenting perspective - and it would also give warnings for trying > >> to enable ips whilst the pipe was off. But you would still need the wait > >> for IPS_ENABLE as confirmation anyway. > > > > Both queued for -next, thanks for the patches&review. > > Hmmm, this patch depends on the "enable planes only after the pipe is > really running" patch. Due to that missing patch, now I get > "[drm:hsw_enable_ips] *ERROR* Timed out waiting for IPS enable" when > booting. I should have said this, sorry :( Ok, I've dropped it again. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
