On Wed, 30 Jun 2021 11:58:25 -0700
John Harrison <john.c.harrison@intel.com> wrote:

> On 6/30/2021 01:22, Martin Peres wrote:
> > On 24/06/2021 10:05, Matthew Brost wrote:  
> >> From: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> >>
> >> Unblock GuC submission on Gen11+ platforms.
> >>
> >> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
> >> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> >> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> >> ---
> >>   drivers/gpu/drm/i915/gt/uc/intel_guc.h            |  1 +
> >>   drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c |  8 ++++++++
> >>   drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h |  3 +--
> >>   drivers/gpu/drm/i915/gt/uc/intel_uc.c             | 14 +++++++++-----
> >>   4 files changed, 19 insertions(+), 7 deletions(-)
> >>

...

> >> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c 
> >> b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> >> index 7a69c3c027e9..61be0aa81492 100644
> >> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> >> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> >> @@ -34,8 +34,15 @@ static void uc_expand_default_options(struct 
> >> intel_uc *uc)
> >>           return;
> >>       }
> >>   -    /* Default: enable HuC authentication only */
> >> -    i915->params.enable_guc = ENABLE_GUC_LOAD_HUC;
> >> +    /* Intermediate platforms are HuC authentication only */
> >> +    if (IS_DG1(i915) || IS_ALDERLAKE_S(i915)) {
> >> +        drm_dbg(&i915->drm, "Disabling GuC only due to old 
> >> platform\n");  
> >
> > This comment does not seem accurate, given that DG1 is barely out, and 
> > ADL is not out yet. How about:
> >
> > "Disabling GuC on untested platforms"?
> >  
> Just because something is not in the shops yet does not mean it is new. 
> Technology is always obsolete by the time it goes on sale.

That is a very good reason to not use terminology like "new", "old",
"current", "modern" etc. at all.

End users like me definitely do not share your interpretation of "old".


Thanks,
pq


> And the issue is not a lack of testing, it is a question of whether we 
> are allowed to change the default on something that has already started 
> being used by customers or not (including pre-release beta customers). 
> I.e. it is basically a political decision not an engineering decision.