[PATCH] drm/xe/gt: Remove redundant num_engine check

[Upadhyay, Tejas]

> -----Original Message-----
> From: Wajdeczko, Michal <Michal.Wajdeczko at intel.com>
> Sent: Friday, March 8, 2024 3:26 PM
> To: Upadhyay, Tejas <tejas.upadhyay at intel.com>; intel-
> xe at lists.freedesktop.org
> Cc: Andi Shyti <andi.shyti at linux.intel.com>; Vishwanathapura, Niranjana
> <niranjana.vishwanathapura at intel.com>
> Subject: Re: [PATCH] drm/xe/gt: Remove redundant num_engine check
> 
> 
> 
> On 08.03.2024 08:03, Tejas Upadhyay wrote:
> > In __xe_gt_apply_ccs_mode num_engines will never be 0 as it is already
> > checked by parent function.
> 
> and that's why we are using xe_assert() instead of explicit checks, so you can't
> say it's redundant
> 
> note that the purpose of xe_assert() inside one function is to enforce the SLA
> for the caller who should be responsible for doing actual runtime checks

The static analysis tool Coverity is also complaining about checking obvious condition on num_engines to be 0. So decided to remove this.

Thanks,
Tejas
> 
> >
> > Fixes: 0d97ecce16bd ("drm/xe: Enable Fixed CCS mode setting")
> > Signed-off-by: Tejas Upadhyay <tejas.upadhyay at intel.com>
> > ---
> >  drivers/gpu/drm/xe/xe_gt_ccs_mode.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/xe/xe_gt_ccs_mode.c
> > b/drivers/gpu/drm/xe/xe_gt_ccs_mode.c
> > index 529fc286cd06..2bbd7b203cc2 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_ccs_mode.c
> > +++ b/drivers/gpu/drm/xe/xe_gt_ccs_mode.c
> > @@ -22,7 +22,7 @@ static void __xe_gt_apply_ccs_mode(struct xe_gt *gt,
> > u32 num_engines)
> >
> >  	xe_assert(xe, xe_gt_ccs_mode_enabled(gt));
> >
> > -	xe_assert(xe, num_engines && num_engines <= num_slices);
> 
> btw, instead of dropping num_engines condition completely this should be
> rather split into two separate xe_asserts():
> 
> 	xe_assert(xe, num_engines);
> 	xe_assert(xe, num_engines <= num_slices);
> 
> > +	xe_assert(xe, num_engines <= num_slices);
> >  	xe_assert(xe, !(num_slices % num_engines));
> >
> >  	/*