On Tue, Jun 16, 2020 at 11:22:32PM +0300, Ville Syrjälä wrote: > On Tue, Jun 16, 2020 at 12:30:56PM -0700, Manasi Navare wrote: > > The Bspec sequence expects us to poll for DDI Idle status > > to be 0 (not idle) with a timeout of 600usecs after enabling the > > DDI BUF CTL. But currently in the driver we just wait for 600usecs > > without polling so add that. > > > > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Cc: Imre Deak <imre.deak@xxxxxxxxx> > > Signed-off-by: Manasi Navare <manasi.d.navare@xxxxxxxxx> > > --- > > drivers/gpu/drm/i915/display/intel_ddi.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c > > index ca7bb2294d2b..de7e15de0bc5 100644 > > --- a/drivers/gpu/drm/i915/display/intel_ddi.c > > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c > > @@ -4023,7 +4023,11 @@ static void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp) > > intel_de_write(dev_priv, DDI_BUF_CTL(port), intel_dp->DP); > > intel_de_posting_read(dev_priv, DDI_BUF_CTL(port)); > > > > - udelay(600); > > + if (wait_for_us(!(intel_de_read(dev_priv, DDI_BUF_CTL(port)) & > > + DDI_BUF_IS_IDLE), > > + 600)) > > + drm_err(&dev_priv->drm, "DDI port:%c buffer idle\n", > > + port_name(port)); > > Another thing I just noticed is that icl+ need this for HDMI as well. > The slightly odd thing is that glk is documented to need this for > DP but not HDMI. But I'm thinking doing it also for glk HDMI should > be fine. > > So I guess to line up with the spec we should: > - fixed >518us enable delay for pre-glk (not sure if polling > would be ok for hsw/bdw/skl) > - poll for enable on glk+ > - fixed 16us disable delay for bxt > - poll for disable on !bxt > > And do it for both DP and HDMI for consistency. So since its different one each platform, should we create a per platform hook like wait_for_non_idle_status or something per platform? Manasi > > > > } > > > > static void intel_ddi_set_link_train(struct intel_dp *intel_dp, > > -- > > 2.19.1 > > -- > Ville Syrjälä > Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
