Re: [PATCH AUTOSEL 5.13 001/189] drm/etnaviv: fix NULL check before some freeing functions is not needed

[Christian König]

Am 07.07.21 um 12:52 schrieb Lucas Stach:
> Am Dienstag, dem 06.07.2021 um 07:11 -0400 schrieb Sasha Levin:
> > From: Tian Tao <tiantao6@xxxxxxxxxxxxx>
> >
> > [ Upstream commit 7d614ab2f20503ed8766363d41f8607337571adf ]
> >
> > fixed the below warning:
> > drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c:84:2-8: WARNING: NULL check
> > before some freeing functions is not needed.
> While the subject contains "fix" this only removes a duplicated NULL
> check, so the code is correct before and after this change.
> Is this really stable material? Doesn't this just add commit noise to
> the stable kernels?

Yeah, agree.

I also had a case where a NULL check was removed in amdgpu and then a 
bit later back ported to stable.

Maybe just use something like "remove superfluous NULL check".

Regards,
Christian.

> Regards,
> Lucas
>
> > Signed-off-by: Tian Tao <tiantao6@xxxxxxxxxxxxx>
> > Acked-by: Christian König <christian.koenig@xxxxxxx>
> > Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 3 +--
> >   1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
> > index b390dd4d60b7..d741b1d735f7 100644
> > --- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
> > +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
> > @@ -80,8 +80,7 @@ static void etnaviv_gem_prime_release(struct etnaviv_gem_object *etnaviv_obj)
> >   	/* Don't drop the pages for imported dmabuf, as they are not
> >   	 * ours, just free the array we allocated:
> >   	 */
> > -	if (etnaviv_obj->pages)
> > -		kvfree(etnaviv_obj->pages);
> > +	kvfree(etnaviv_obj->pages);
> >   
> >   	drm_prime_gem_destroy(&etnaviv_obj->base, etnaviv_obj->sgt);
> >   }