On Thu, Oct 11, 2018 at 2:19 AM Mahesh Kumar <mahesh1.sh.kumar@xxxxxxxxx> wrote:
>
> Hi,
>
> On Wed, Oct 10, 2018 at 11:25 PM Ville Syrjala
> <ville.syrjala@xxxxxxxxxxxxxxx> wrote:
> >
> > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> >
> > The 16Gb DIMM w/a is not applicable to BXT or GLK. Limit it to
> > the appropriate platforms.
> >
> > This was especially harsh on GLK since we don't even try to read
> > the DIMM information on that platforms, hence valid_dimm was
> > always false and thus we always tried to apply the w/a.
> > Furthermore the w/a pushed the level 0 latency above the
> > level 1 latency, which doesn't really make sense.
> >
> > Cc: Mahesh Kumar <mahesh1.kumar@xxxxxxxxx>
> > Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> > Fixes: 86b592876cb6 ("drm/i915: Implement 16GB dimm wa for latency level-0")
> > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/intel_pm.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index 1392aa56a55a..a51cd09bbf75 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -2881,8 +2881,9 @@ static void intel_read_wm_latency(struct drm_i915_private *dev_priv,
> > * any underrun. If not able to get Dimm info assume 16GB dimm
> > * to avoid any underrun.
> > */
> > - if (!dev_priv->dram_info.valid_dimm ||
> > - dev_priv->dram_info.is_16gb_dimm)
> > + if (!IS_GEN9_LP(dev_priv) &&
> > + (!dev_priv->dram_info.valid_dimm ||
> > + dev_priv->dram_info.is_16gb_dimm))
> > wm[0] += 1;
>
> I would rather prefer to update "intel_get_dram_info" to fill
> valid_dimm and is_16gb_dimm info properly
>
> - if (INTEL_GEN(dev_priv) < 9 || IS_GEMINILAKE(dev_priv))
> + if (INTEL_GEN(dev_priv) < 9 )
> return;
>
> + if (IS_GEN9_LP(dev_priv)) {
> + dram_info->valid_dimm = true;
> + dram_info->is_16gb_dimm = false;
> + }
> +
> +
We don't want to proceed for GLK. So, something like:
+ if (IS_GEN9_LP(dev_priv)) {
+ dram_info->valid_dimm = true;
+ dram_info->is_16gb_dimm = false;
+ }
+
if (INTEL_GEN(dev_priv) < 9 || IS_GEMINILAKE(dev_priv))
return;
-Mahesh
>
> -Mahesh
>
> >
> > } else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
> > --
> > 2.18.1
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
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