2021-10-18 03:30:52

by Christophe JAILLET

[permalink] [raw]
Subject: [PATCH] media: tw5864: Simplify 'tw5864_finidev()'

Some resources are allocated with 'pci_request_regions()', so use
'pci_release_regions()' to free them, instead of a verbose
'release_mem_region()'.

There is no point in calling 'devm_kfree()'. The corresponding resource is
managed, so it will be fried automatically.

Signed-off-by: Christophe JAILLET <[email protected]>
---
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


2021-10-19 10:39:02

by Kieran Bingham

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

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.

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

Reviewed-by: Kieran Bingham <[email protected]>

> 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 <[email protected]>
> ---
> 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
>

2021-10-19 17:49:42

by Christophe JAILLET

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

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 <[email protected]>
>
>> 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 <[email protected]>
>> ---
>> 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
>>
>