Re: [PATCH 1/3] media: vimc: initialize vim entity pointers to NULL

[Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxxxx>]

Hi Dafna, hi Helen,

W dniu 01.10.2019 o 19:19, Helen Koike pisze:
> Hi Dafna,
>
> On 10/1/19 1:50 PM, Dafna Hirschfeld wrote:
> > since NULL value for vimc entity pointer indicates
> > that entity creation failed and this is tested, the
> > pointers should be initialized to NULL.
>
> Nice catch :)
>
> > Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
> > ---
> >   drivers/media/platform/vimc/vimc-core.c | 8 +++-----
> >   1 file changed, 3 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/media/platform/vimc/vimc-core.c b/drivers/media/platform/vimc/vimc-core.c
> > index 6e3e5c91ae39..32a79e578b78 100644
> > --- a/drivers/media/platform/vimc/vimc-core.c
> > +++ b/drivers/media/platform/vimc/vimc-core.c
> > @@ -160,19 +160,17 @@ static int vimc_create_links(struct vimc_device *vimc)
> >   static int vimc_add_subdevs(struct vimc_device *vimc)
> >   {
> >   	unsigned int i;
> > -	struct vimc_ent_device *ved;
> >   
> >   	for (i = 0; i < vimc->pipe_cfg->num_ents; i++) {
> >   		dev_dbg(&vimc->pdev.dev, "new entity for %s\n",
> >   			vimc->pipe_cfg->ents[i].name);
> > -		ved = vimc->pipe_cfg->ents[i].add(vimc,
> > +		vimc->ent_devs[i] = vimc->pipe_cfg->ents[i].add(vimc,
> >   					vimc->pipe_cfg->ents[i].name);
> > -		if (!ved) {
> > +		if (!vimc->ent_devs[i]) {
> >   			dev_err(&vimc->pdev.dev, "add new entity for %s\n",
> >   				vimc->pipe_cfg->ents[i].name);
> >   			return -EINVAL;
> >   		}
> > -		vimc->ent_devs[i] = ved;
> >   	}
> >   	return 0;
> >   }
>
> I believe just the kcalloc bellow should fix the issue.
> But if you want to do this cleanup anyway, I would suggest sending a separate patch for it.
>
> > @@ -199,7 +197,7 @@ static int vimc_register_devices(struct vimc_device *vimc)
> >   	}
> >   
> >   	/* allocate ent_devs */
> > -	vimc->ent_devs = kmalloc_array(vimc->pipe_cfg->num_ents,
> > +	vimc->ent_devs = kcalloc(vimc->pipe_cfg->num_ents,
> >   				       sizeof(*vimc->ent_devs),
> >   				       GFP_KERNEL);
>
> Could you fix the alignment of the params here?

Isn't the above change (kmalloc_array() to kcalloc()) alone enough
to ensure the promise from the patch title is fulfilled?

In other words, why remove the "ved" local variable in vimc_add_subdevs()?

Andrzej