[PATCH] rt2x00pci: Disable memory-write-invalidate when the driver exits

[PATCH] rt2x00pci: Disable memory-write-invalidate when the driver exits

[Jia-Ju Bai]

The driver calls pci_set_mwi to enable memory-write-invalidate when it
is initialized, but does not call pci_clear_mwi when it is removed. Many
other drivers calls pci_clear_mwi when pci_set_mwi is called, such as
r8169, 8139cp and e1000.

This patch adds pci_clear_mwi in error handling and removal procedure, 
which can fix the problem.

Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
---
 drivers/net/wireless/rt2x00/rt2x00pci.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/wireless/rt2x00/rt2x00pci.c b/drivers/net/wireless/rt2x00/rt2x00pci.c
index d93db4b..eb6dbcd 100644
--- a/drivers/net/wireless/rt2x00/rt2x00pci.c
+++ b/drivers/net/wireless/rt2x00/rt2x00pci.c
@@ -149,6 +149,7 @@ exit_free_device:
 	ieee80211_free_hw(hw);
 
 exit_release_regions:
+	pci_clear_mwi(pci_dev);
 	pci_release_regions(pci_dev);
 
 exit_disable_device:
@@ -173,6 +174,7 @@ void rt2x00pci_remove(struct pci_dev *pci_dev)
 	/*
 	 * Free the PCI device data.
 	 */
+	pci_clear_mwi(pci_dev);
 	pci_disable_device(pci_dev);
 	pci_release_regions(pci_dev);
 }
-- 
1.7.9.5

Re: [PATCH] rt2x00pci: Disable memory-write-invalidate when the driver exits

[Helmut Schaa]

On Mon, Jan 4, 2016 at 8:55 AM, Jia-Ju Bai <baijiaju1990@163.com> wrote:
> The driver calls pci_set_mwi to enable memory-write-invalidate when it
> is initialized, but does not call pci_clear_mwi when it is removed. Many
> other drivers calls pci_clear_mwi when pci_set_mwi is called, such as
> r8169, 8139cp and e1000.
>
> This patch adds pci_clear_mwi in error handling and removal procedure,
> which can fix the problem.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>

Looks good to me.
Does this fix any actual issue?
If yes it might we worth to mention it in the commit message.
Helmut


> ---
>  drivers/net/wireless/rt2x00/rt2x00pci.c |    2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/wireless/rt2x00/rt2x00pci.c b/drivers/net/wireless/rt2x00/rt2x00pci.c
> index d93db4b..eb6dbcd 100644
> --- a/drivers/net/wireless/rt2x00/rt2x00pci.c
> +++ b/drivers/net/wireless/rt2x00/rt2x00pci.c
> @@ -149,6 +149,7 @@ exit_free_device:
>         ieee80211_free_hw(hw);
>
>  exit_release_regions:
> +       pci_clear_mwi(pci_dev);
>         pci_release_regions(pci_dev);
>
>  exit_disable_device:
> @@ -173,6 +174,7 @@ void rt2x00pci_remove(struct pci_dev *pci_dev)
>         /*
>          * Free the PCI device data.
>          */
> +       pci_clear_mwi(pci_dev);
>         pci_disable_device(pci_dev);
>         pci_release_regions(pci_dev);
>  }
> --
> 1.7.9.5
>
>

Re: [PATCH] rt2x00pci: Disable memory-write-invalidate when the driver exits

[Jia-Ju Bai]

On 01/05/2016 12:50 AM, Helmut Schaa wrote:
> On Mon, Jan 4, 2016 at 8:55 AM, Jia-Ju Bai<baijiaju1990@163.com>  wrote:
>> The driver calls pci_set_mwi to enable memory-write-invalidate when it
>> is initialized, but does not call pci_clear_mwi when it is removed. Many
>> other drivers calls pci_clear_mwi when pci_set_mwi is called, such as
>> r8169, 8139cp and e1000.
>>
>> This patch adds pci_clear_mwi in error handling and removal procedure,
>> which can fix the problem.
>>
>> Signed-off-by: Jia-Ju Bai<baijiaju1990@163.com>
> Looks good to me.
> Does this fix any actual issue?
> If yes it might we worth to mention it in the commit message.
> Helmut
>

Lacking pci_clear_mwi may cause a resource-release omission,
but this omission may not cause obvious issues.
For reliability, it is better to add pci_clear_mwi in the driver.
Many other drivers do so, such as r8169, 8139cp and e1000.


Jia-Ju Bai

Re: [PATCH] rt2x00pci: Disable memory-write-invalidate when the driver exits

[Helmut Schaa]

On Tue, Jan 5, 2016 at 2:27 AM, Jia-Ju Bai <baijiaju1990@163.com> wrote:
> On 01/05/2016 12:50 AM, Helmut Schaa wrote:
>>
>> On Mon, Jan 4, 2016 at 8:55 AM, Jia-Ju Bai<baijiaju1990@163.com>  wrote:
>>>
>>> The driver calls pci_set_mwi to enable memory-write-invalidate when it
>>> is initialized, but does not call pci_clear_mwi when it is removed. Many
>>> other drivers calls pci_clear_mwi when pci_set_mwi is called, such as
>>> r8169, 8139cp and e1000.
>>>
>>> This patch adds pci_clear_mwi in error handling and removal procedure,
>>> which can fix the problem.
>>>
>>> Signed-off-by: Jia-Ju Bai<baijiaju1990@163.com>
>>
>> Looks good to me.
>> Does this fix any actual issue?
>> If yes it might we worth to mention it in the commit message.
>> Helmut
>>
>
> Lacking pci_clear_mwi may cause a resource-release omission,
> but this omission may not cause obvious issues.
> For reliability, it is better to add pci_clear_mwi in the driver.
> Many other drivers do so, such as r8169, 8139cp and e1000.

Thanks for clarification, fine with me then.

Acked-by: Helmut Schaa <helmut.schaa@googlemail.com>

Re: rt2x00pci: Disable memory-write-invalidate when the driver exits

[Kalle Valo]

> The driver calls pci_set_mwi to enable memory-write-invalidate when it
> is initialized, but does not call pci_clear_mwi when it is removed. Many
> other drivers calls pci_clear_mwi when pci_set_mwi is called, such as
> r8169, 8139cp and e1000.
> 
> This patch adds pci_clear_mwi in error handling and removal procedure, 
> which can fix the problem.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
> Acked-by: Helmut Schaa <helmut.schaa@googlemail.com>

Thanks, applied to wireless-drivers-next.git.

Kalle Valo