Hi Lucas, On Mon, Sep 12, 2022 at 11:12:47AM -0700, Lucas De Marchi wrote: > On Mon, Sep 12, 2022 at 06:59:53PM +0200, Andi Shyti wrote: > > Hi Lucas, > > > > On Mon, Sep 12, 2022 at 09:19:38AM -0700, Lucas De Marchi wrote: > > > Support for reading the fuses to check what are the Link Copy engines > > > was added in commit ad5f74f34201 ("drm/i915/pvc: read fuses for link > > > copy engines"). However they were added unconditionally because the > > > FUSE3 register is present since graphics version 10. > > > > > > However the bitfield with meml3 fuses only exists since graphics version > > > 12. Moreover, Link Copy engines are currently only available in PVC. > > > Tying additional copy engines to the meml3 fuses is not correct for > > > other platforms. > > > > > > Make sure there is a check for `12.60 <= ver < 12.70`. Later platforms > > > may extend this function later if it's needed to fuse off copy engines. > > > > > > Currently it's harmless as the Link Copy engines are still not exported: > > > info->engine_mask only has BCS0 set and the register is only read for > > > platforms that do have it. > > > > > > Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> > > > > > > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c > > > index 814f83b5fe59..1f7188129cd1 100644 > > > --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c > > > +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c > > > @@ -764,6 +764,10 @@ static void engine_mask_apply_copy_fuses(struct intel_gt *gt) > > > unsigned long meml3_mask; > > > unsigned long quad; > > > > > > + if (!(GRAPHICS_VER_FULL(i915) >= IP_VER(12, 60) && > > > + GRAPHICS_VER_FULL(i915) < IP_VER(12, 70))) > > > + return; > > > + > > > > Isn't it easier if you wrote > > > > if (GRAPHICS_VER_FULL(i915) < IP_VER(12, 60) || > > GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70)) > > return; > > > > ? > > > > You save a parenthesis and a negation '!'. > > but that makes it wrong. I'd really want the range > 12.60 <= version < 12.70, so it applies to PVC but is then disabled > again for MTL. But it's negated... so that if it's not in the range, it's outside of the range... right? NOT(12.60 <= ver < 12.70) <--- you wrote is the same as: ver < 12.60 or ver >= 12.70 <--- I suggested and it would mean (just to see if I'm not getting confused by something and the negations do always confuse me): 12.60 12.70 return | | return ver: ------------[--------------[--------------- But it's the same, taht's why I r-b it anyway. > Depending on how this evolves for future platforms, we > may change it to a feature flag or just check by platform > name. For now I think this is the most future-proof option. yes, I got the point and I think it's fine. Andi > Lucas De Marchi > > > > > Anyway, looks good: > > > > Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx> > > > > Andi > > > > > meml3_mask = intel_uncore_read(gt->uncore, GEN10_MIRROR_FUSE3); > > > meml3_mask = REG_FIELD_GET(GEN12_MEML3_EN_MASK, meml3_mask); > > > > > > > > > -- > > > b4 0.10.0-dev-df873