RE: [PATCH] drm/i915: Set wedged if enable guc communication failed

["Dong, Zhanjun" <zhanjun.dong@xxxxxxxxx>]

Thanks Jani.
Updated patch sent, let me know if you have any comments.

Regards,
Zhanjun

> -----Original Message-----
> From: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
> Sent: February 27, 2023 6:30 AM
> To: Dong, Zhanjun <zhanjun.dong@xxxxxxxxx>; intel-
> gfx@xxxxxxxxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: Dong, Zhanjun <zhanjun.dong@xxxxxxxxx>
> Subject: Re: [PATCH] drm/i915: Set wedged if enable guc communication
> failed
> 
> On Fri, 24 Feb 2023, Zhanjun Dong <zhanjun.dong@xxxxxxxxx> wrote:
> > Add err code check for enable_communication on resume path, set
> wedged if failed.
> 
> I can see that this is *what* the code does, but the commit message should
> answer the question *why*.
> 
> >
> > Signed-off-by: Zhanjun Dong <zhanjun.dong@xxxxxxxxx>
> > ---
> >  drivers/gpu/drm/i915/gt/intel_gt_pm.c | 5 ++++-
> > drivers/gpu/drm/i915/gt/uc/intel_uc.c | 9 +++++++--
> >  2 files changed, 11 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm.c
> > b/drivers/gpu/drm/i915/gt/intel_gt_pm.c
> > index cef3d6f5c34e..f3bb7cbbd293 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_gt_pm.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_gt_pm.c
> > @@ -401,8 +401,11 @@ int intel_gt_runtime_resume(struct intel_gt *gt)
> >  	intel_ggtt_restore_fences(gt->ggtt);
> >
> >  	ret = intel_uc_runtime_resume(&gt->uc);
> > -	if (ret)
> > +	if (ret) {
> > +		/* Set wedge if uc resume failed */
> 
> This comment is just a reiteration of the C code in English, but doesn't
> provide any useful additional information.
> 
> BR,
> Jani.
> 
> > +		intel_gt_set_wedged(gt);
> >  		return ret;
> > +	}
> >
> >  	return 0;
> >  }
> > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> > b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> > index 6648691bd645..d4f428acf20a 100644
> > --- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> > +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> > @@ -698,8 +698,13 @@ static int __uc_resume(struct intel_uc *uc, bool
> enable_communication)
> >  	/* Make sure we enable communication if and only if it's disabled */
> >  	GEM_BUG_ON(enable_communication ==
> intel_guc_ct_enabled(&guc->ct));
> >
> > -	if (enable_communication)
> > -		guc_enable_communication(guc);
> > +	if (enable_communication) {
> > +		err = guc_enable_communication(guc);
> > +		if (err) {
> > +			guc_dbg(guc, "Failed to resume, %pe", ERR_PTR(err));
> > +			return err;
> > +		}
> > +	}
> >
> >  	/* If we are only resuming GuC communication but not reloading
> >  	 * GuC, we need to ensure the ARAT timer interrupt is enabled
> 
> --
> Jani Nikula, Intel Open Source Graphics Center