Re: [PATCH] media: tw5864: Simplify 'tw5864_finidev()'

[Christophe JAILLET]

Le 19/10/2021 à 12:35, Kieran Bingham a écrit :
> Quoting Christophe JAILLET (2021-10-16 09:40:29)
> > Some resources are allocated with 'pci_request_regions()', so use
> > 'pci_release_regions()' to free them, instead of a verbose
> > 'release_mem_region()'.
>
> And the driver was even already using pci_release_regions() in
> tw5864_initdev(), so indeed this makes it more consistent too.
>
> I'm curious that tw5864_initdev() calls pci_enable_device() (and
> pci_disable_device in it's error path), while tw5864_finidev() doesn't.

I agree with you. I should have spotted it when I've looked at the probe 
and remove functions :(

> Would you like to submit a patch to fix that on top of this one? or should I?

Either way is fine for me.
If it's fine for you to fix it, I leave it to you.

A more invasive fix could be to switch to 'pcim_enable_device()' and 
remove both 'pci_release_regions()' and 'pci_disable_device()' calls.

CJ

> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
>
> > There is no point in calling 'devm_kfree()'. The corresponding resource is
> > managed, so it will be fried automatically.
>
> Indeed.
>
> > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> > ---
> >   drivers/media/pci/tw5864/tw5864-core.c | 4 +---
> >   1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/drivers/media/pci/tw5864/tw5864-core.c b/drivers/media/pci/tw5864/tw5864-core.c
> > index 23d3cae54a5d..fee3b7711901 100644
> > --- a/drivers/media/pci/tw5864/tw5864-core.c
> > +++ b/drivers/media/pci/tw5864/tw5864-core.c
> > @@ -333,11 +333,9 @@ static void tw5864_finidev(struct pci_dev *pci_dev)
> >   
> >          /* release resources */
> >          iounmap(dev->mmio);
> > -       release_mem_region(pci_resource_start(pci_dev, 0),
> > -                          pci_resource_len(pci_dev, 0));
> > +       pci_release_regions(pci_dev);
> >   
> >          v4l2_device_unregister(&dev->v4l2_dev);
> > -       devm_kfree(&pci_dev->dev, dev);
> >   }
> >   
> >   static struct pci_driver tw5864_pci_driver = {
> > --
> > 2.30.2