Patchwork [-v2] PCI: Avoid initialize MSI/MSIX if device power state != PCI_D0

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Submitter Yijing Wang
Date Oct. 10, 2013, 12:41 p.m.
Message ID <1381408907-11724-1-git-send-email-wangyijing@huawei.com>
Download mbox | patch
Permalink /patch/282241/
State Superseded
Headers show

Comments

Yijing Wang - Oct. 10, 2013, 12:41 p.m.
Currently, if device power state != PCI_D0, we still initialize
device MSI/MSIX, but we won't write the MSI message to device
MSI/MSIX registers. It's weird, we don't configure MSI/MSIX
registers properly, but pci_enable_msi() or pci_enable_msix()
return success, and even these registers will never be updated later.
So I think it should return error if device power state != PCI_D0.

---

v1->v2: keep __write_msi_msg() function device power state statement,
	    because Ben Hutchings point out this function may be called
		during device in D3 state to set irq affinity. We should not
		touch that.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
---
 drivers/pci/msi.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
Ben Hutchings - Oct. 10, 2013, 12:45 p.m.
On Thu, 2013-10-10 at 20:41 +0800, Yijing Wang wrote:
> Currently, if device power state != PCI_D0, we still initialize
> device MSI/MSIX, but we won't write the MSI message to device
> MSI/MSIX registers. It's weird, we don't configure MSI/MSIX
> registers properly, but pci_enable_msi() or pci_enable_msix()
> return success, and even these registers will never be updated later.
> So I think it should return error if device power state != PCI_D0.
> 
> ---
> 
> v1->v2: keep __write_msi_msg() function device power state statement,
> 	    because Ben Hutchings point out this function may be called
> 		during device in D3 state to set irq affinity. We should not
> 		touch that.
> 
> Signed-off-by: Yijing Wang <wangyijing@huawei.com>

S-o-b needs to be above the first '---' but perhaps Bjorn can fix that
up before applying.

Acked-by: Ben Hutchings <bhutchings@solarflare.com>

> ---
>  drivers/pci/msi.c |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index d5f90d6..604265c 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -831,7 +831,7 @@ int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
>  	int status, maxvec;
>  	u16 msgctl;
>  
> -	if (!dev->msi_cap)
> +	if (!dev->msi_cap || dev->current_state != PCI_D0)
>  		return -EINVAL;
>  
>  	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
> @@ -862,7 +862,7 @@ int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec)
>  	int ret, nvec;
>  	u16 msgctl;
>  
> -	if (!dev->msi_cap)
> +	if (!dev->msi_cap || dev->current_state != PCI_D0)
>  		return -EINVAL;
>  
>  	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
> @@ -955,7 +955,7 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
>  	int status, nr_entries;
>  	int i, j;
>  
> -	if (!entries || !dev->msix_cap)
> +	if (!entries || !dev->msix_cap || dev->current_state != PCI_D0)
>  		return -EINVAL;
>  
>  	status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);
Yijing Wang - Oct. 10, 2013, 12:53 p.m.
On 2013/10/10 20:45, Ben Hutchings wrote:
> On Thu, 2013-10-10 at 20:41 +0800, Yijing Wang wrote:
>> Currently, if device power state != PCI_D0, we still initialize
>> device MSI/MSIX, but we won't write the MSI message to device
>> MSI/MSIX registers. It's weird, we don't configure MSI/MSIX
>> registers properly, but pci_enable_msi() or pci_enable_msix()
>> return success, and even these registers will never be updated later.
>> So I think it should return error if device power state != PCI_D0.
>>
>> ---
>>
>> v1->v2: keep __write_msi_msg() function device power state statement,
>> 	    because Ben Hutchings point out this function may be called
>> 		during device in D3 state to set irq affinity. We should not
>> 		touch that.
>>
>> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
> 
> S-o-b needs to be above the first '---' but perhaps Bjorn can fix that
> up before applying.
> 
> Acked-by: Ben Hutchings <bhutchings@solarflare.com>


Thanks very much, I will update it, so Bjorn can apply it easily.

> 
>> ---
>>  drivers/pci/msi.c |    6 +++---
>>  1 files changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
>> index d5f90d6..604265c 100644
>> --- a/drivers/pci/msi.c
>> +++ b/drivers/pci/msi.c
>> @@ -831,7 +831,7 @@ int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
>>  	int status, maxvec;
>>  	u16 msgctl;
>>  
>> -	if (!dev->msi_cap)
>> +	if (!dev->msi_cap || dev->current_state != PCI_D0)
>>  		return -EINVAL;
>>  
>>  	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
>> @@ -862,7 +862,7 @@ int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec)
>>  	int ret, nvec;
>>  	u16 msgctl;
>>  
>> -	if (!dev->msi_cap)
>> +	if (!dev->msi_cap || dev->current_state != PCI_D0)
>>  		return -EINVAL;
>>  
>>  	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
>> @@ -955,7 +955,7 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
>>  	int status, nr_entries;
>>  	int i, j;
>>  
>> -	if (!entries || !dev->msix_cap)
>> +	if (!entries || !dev->msix_cap || dev->current_state != PCI_D0)
>>  		return -EINVAL;
>>  
>>  	status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);
>

Patch

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d5f90d6..604265c 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -831,7 +831,7 @@  int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
 	int status, maxvec;
 	u16 msgctl;
 
-	if (!dev->msi_cap)
+	if (!dev->msi_cap || dev->current_state != PCI_D0)
 		return -EINVAL;
 
 	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
@@ -862,7 +862,7 @@  int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec)
 	int ret, nvec;
 	u16 msgctl;
 
-	if (!dev->msi_cap)
+	if (!dev->msi_cap || dev->current_state != PCI_D0)
 		return -EINVAL;
 
 	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
@@ -955,7 +955,7 @@  int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
 	int status, nr_entries;
 	int i, j;
 
-	if (!entries || !dev->msix_cap)
+	if (!entries || !dev->msix_cap || dev->current_state != PCI_D0)
 		return -EINVAL;
 
 	status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);