[Intel-gfx] [PATCH] drm/i915/gt: Use the correct error value when kernel_context() fails

[Upadhyay, Tejas]

> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of
> Andrzej Hajda
> Sent: Thursday, June 1, 2023 6:14 PM
> To: Andi Shyti <andi.shyti at linux.intel.com>; Intel GFX <intel-
> gfx at lists.freedesktop.org>; DRI Devel <dri-devel at lists.freedesktop.org>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>; stable at vger.kernel.org; Dan
> Carpenter <dan.carpenter at linaro.org>; Andi Shyti <andi.shyti at kernel.org>
> Subject: Re: [Intel-gfx] [PATCH] drm/i915/gt: Use the correct error value
> when kernel_context() fails
> 
> On 26.05.2023 14:41, Andi Shyti wrote:
> > kernel_context() returns an error pointer. Use pointer-error
> > conversion functions to evaluate its return value, rather than
> > checking for a '0' return.
> >
> > Fixes: eb5c10cbbc2f ("drm/i915: Remove I915_USER_PRIORITY_SHIFT")
> > Reported-by: Dan Carpenter <dan.carpenter at linaro.org>
> > Signed-off-by: Andi Shyti <andi.shyti at linux.intel.com>
> > Cc: Chris Wilson < chris at chris-wilson.co.uk>
> > Cc: <stable at vger.kernel.org> # v5.13+
> 
> Reviewed-by: Andrzej Hajda <andrzej.hajda at intel.com>
> 
> Regards
> Andrzej
> 
> > ---
> >   drivers/gpu/drm/i915/gt/selftest_execlists.c | 12 ++++++++----
> >   1 file changed, 8 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gt/selftest_execlists.c
> > b/drivers/gpu/drm/i915/gt/selftest_execlists.c
> > index 736b89a8ecf54..4202df5b8c122 100644
> > --- a/drivers/gpu/drm/i915/gt/selftest_execlists.c
> > +++ b/drivers/gpu/drm/i915/gt/selftest_execlists.c
> > @@ -1530,8 +1530,8 @@ static int live_busywait_preempt(void *arg)
> >   	struct drm_i915_gem_object *obj;
> >   	struct i915_vma *vma;
> >   	enum intel_engine_id id;
> > -	int err = -ENOMEM;
> >   	u32 *map;
> > +	int err;

We could initialize err with 0 and remove err = 0 assignment below but leaving up to you. 

> >
> >   	/*
> >   	 * Verify that even without HAS_LOGICAL_RING_PREEMPTION, we
> can @@
> > -1539,13 +1539,17 @@ static int live_busywait_preempt(void *arg)
> >   	 */
> >
> >   	ctx_hi = kernel_context(gt->i915, NULL);
> > -	if (!ctx_hi)
> > -		return -ENOMEM;
> > +	if (IS_ERR(ctx_hi))
> > +		return PTR_ERR(ctx_hi);
> > +
> >   	ctx_hi->sched.priority = I915_CONTEXT_MAX_USER_PRIORITY;
> >
> >   	ctx_lo = kernel_context(gt->i915, NULL);
> > -	if (!ctx_lo)
> > +	if (IS_ERR(ctx_lo)) {
> > +		err = PTR_ERR(ctx_lo);
> >   		goto err_ctx_hi;
> > +	}
> > +

Looks fine,
Acked-by: Tejas Upadhyay <tejas.upadhyay at intel.com>

> >   	ctx_lo->sched.priority = I915_CONTEXT_MIN_USER_PRIORITY;
> >
> >   	obj = i915_gem_object_create_internal(gt->i915, PAGE_SIZE);