[Intel-gfx] [PATCH v2 2/2] drm/i915/tgl: Read SAGV block time from PCODE

[James Ausmus]

On Mon, Oct 07, 2019 at 01:15:24PM +0300, Ville Syrjälä wrote:
> On Fri, Oct 04, 2019 at 02:51:34PM -0700, James Ausmus wrote:
> > On Fri, Oct 04, 2019 at 01:55:46PM -0700, Lucas De Marchi wrote:
> > > On Fri, Sep 27, 2019 at 03:24:27PM -0700, James Ausmus wrote:
> > > >Starting from TGL, we now need to read the SAGV block time via a PCODE
> > > >mailbox, rather than having a static value.
> > > >
> > > >BSpec: 49326
> > > >
> > > >v2: Fix up pcode val data type (Ville), tighten variable scope (Ville)
> > > >
> > > >Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > >Cc: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> > > >Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> > > >Signed-off-by: James Ausmus <james.ausmus at intel.com>
> > > >Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > >---
> > > > drivers/gpu/drm/i915/i915_reg.h |  1 +
> > > > drivers/gpu/drm/i915/intel_pm.c | 15 ++++++++++++++-
> > > > 2 files changed, 15 insertions(+), 1 deletion(-)
> > > >
> > > >diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > > >index 058aa5ca8b73..6a45df9dad9c 100644
> > > >--- a/drivers/gpu/drm/i915/i915_reg.h
> > > >+++ b/drivers/gpu/drm/i915/i915_reg.h
> > > >@@ -8869,6 +8869,7 @@ enum {
> > > > #define     GEN9_SAGV_DISABLE			0x0
> > > > #define     GEN9_SAGV_IS_DISABLED		0x1
> > > > #define     GEN9_SAGV_ENABLE			0x3
> > > >+#define GEN12_PCODE_READ_SAGV_BLOCK_TIME_US	0x23
> > > > #define GEN6_PCODE_DATA				_MMIO(0x138128)
> > > > #define   GEN6_PCODE_FREQ_IA_RATIO_SHIFT	8
> > > > #define   GEN6_PCODE_FREQ_RING_RATIO_SHIFT	16
> > > >diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > > >index b413a7f3bc5d..13721ba44013 100644
> > > >--- a/drivers/gpu/drm/i915/intel_pm.c
> > > >+++ b/drivers/gpu/drm/i915/intel_pm.c
> > > >@@ -3645,7 +3645,20 @@ intel_has_sagv(struct drm_i915_private *dev_priv)
> > > > static void
> > > > skl_setup_sagv_block_time(struct drm_i915_private *dev_priv)
> > > > {
> > > >-	if (IS_GEN(dev_priv, 11)) {
> > > >+	if (INTEL_GEN(dev_priv) >= 12) {
> > > 
> > > sagv will still never be enabled for TGL. Are you going to revert 
> > > 8ffa4392a32e ("drm/i915/tgl: disable SAGV temporarily")
> > > in a separete patch?
> > 
> > Yes, that's the idea - we land these two patches, then once HSD
> > 1409542895 gets resolved, we revert 8ffa4392a32e and everything Just
> > Works. ;)
> 
> The whole sagv stuff is wrong for icl+. Stan is attempting to remedy
> that.

Well, we'll at least need to do this read of the block time - do you
think these two patches can land in the meantime, to help prep the TGL
path for actually working when Stan's work lands?

Thanks!

-James

> 
> > 
> > -James
> > 
> > > 
> > > Lucas De Marchi
> > > 
> > > >+		u32 val = 0;
> > > >+		int ret;
> > > >+
> > > >+		ret = sandybridge_pcode_read(dev_priv,
> > > >+					     GEN12_PCODE_READ_SAGV_BLOCK_TIME_US,
> > > >+					     &val, NULL);
> > > >+		if (!ret) {
> > > >+			dev_priv->sagv_block_time_us = val;
> > > >+			return;
> > > >+		}
> > > >+
> > > >+		DRM_DEBUG_DRIVER("Couldn't read SAGV block time!\n");
> > > >+	} else if (IS_GEN(dev_priv, 11)) {
> > > > 		dev_priv->sagv_block_time_us = 10;
> > > > 		return;
> > > > 	} else if (IS_GEN(dev_priv, 10)) {
> > > >-- 
> > > >2.22.1
> > > >
> 
> -- 
> Ville Syrjälä
> Intel