> On Wed, Mar 29, 2017 at 05:02:47PM +0800, Xiong Zhang wrote: > > In a virtual passthrough environment, the ISA bridge isn't able to > > be passed through. So pch_id couldn't be gotten from ISA bridge, but > > pch_id is used to identify LPT_H and LPT_LP, this patch set pch_id > > according to IGD type. > > > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99938 > > > > Signed-off-by: Xiong Zhang <xiong.y.zhang@xxxxxxxxx> > > --- > > drivers/gpu/drm/i915/i915_drv.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.c > b/drivers/gpu/drm/i915/i915_drv.c > > index 8b807a9..32a9bff 100644 > > --- a/drivers/gpu/drm/i915/i915_drv.c > > +++ b/drivers/gpu/drm/i915/i915_drv.c > > @@ -135,9 +135,17 @@ static enum intel_pch intel_virt_detect_pch(struct > drm_i915_private *dev_priv) > > DRM_DEBUG_KMS("Assuming CouarPoint PCH\n"); > > } else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) { > > ret = PCH_LPT; > > + if (IS_HSW_ULT(dev_priv) || IS_BDW_ULT(dev_priv)) > > + dev_priv->pch_id = INTEL_PCH_LPT_LP_DEVICE_ID_TYPE; > > + else > > + dev_priv->pch_id = INTEL_PCH_LPT_DEVICE_ID_TYPE; > > DRM_DEBUG_KMS("Assuming LynxPoint PCH\n"); > > } else if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv)) { > > ret = PCH_SPT; > > + if (IS_SKL_ULT(dev_priv) || IS_KBL_ULT(dev_priv)) > > + dev_priv->pch_id = INTEL_PCH_SPT_LP_DEVICE_ID_TYPE; > > + else > > + dev_priv->pch_id = INTEL_PCH_SPT_DEVICE_ID_TYPE; > > I'm not 100% sure the ULT/ULX <=> LP thing always holds. I *think* it > should but I've never been able to convince myself totally. [Zhang, Xiong Y] For BDW ULT/ULX, it should be LP. A picture from https://gfxspecs.intel.com/Predator/Home/Index/4216 could confirm this. For HSW ULT/ULX, I couldn't find a material to confirm this. Anyway I copy this condition from the WARN_ON() in intel_detect_pch() For SKL/KBL ULT/ULX, I couldn't find a material to confirm this neither. > As far as KBL goes, maybe we want PCH_KBP for it? Although I don't actually > know why we even make the distinction between the two since they seem > identical for us, and we don't distinguish LPT vs. WPT either. Rodrigo? [Zhang, Xiong Y] For PCH_KBP, I couldn't find out which KBL type will co-work with it. As the real ISA Bridge doesn't exist in a emulated guest machine, we couldn't get the real and accurate pch_id in guest. In such passthrough virtual environment, the only real HW is IGD which is passed through to guest, we could only assume the pch_id from this IGD. Fortunately pch_id is only used to identify LPT_LP and LPT_H currently. Without this patch, pch_id is totally wrong. And on LPT_LP platform without this patch, the local HDMI/DP display couldn't lightup when guest boot up. But this patch could only remedy part of pch_id. Currently I have two plans to improve this patch: 1) only remain pch_id assuming for HSW and BDW, as this is really we need to fix the bug. Delete pch_id assuming for SKL and KBL, as currently i915 driver don't use it. 2) Claim this patch's limitation in commit message. Any suggestion ? > > DRM_DEBUG_KMS("Assuming SunrisePoint PCH\n"); > > } > > > > -- > > 1.9.1 > > > > _______________________________________________ > > Intel-gfx mailing list > > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx > > -- > Ville Syrjälä > Intel OTC _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
