[PATCH] [e1000] Lower the MSI unavailable message to INFO priority

[PATCH] [e1000] Lower the MSI unavailable message to INFO priority

[H. Peter Anvin]

Currently, if MSI is enabled but unavailable the e1000 prints an error
message "Unable to allocate MSI interrupt Error" with ERR priority.
This is confusing to users since this is not a functionality error;
the driver will immediately afterwards try to acquire a conventional
PIC/APIC interrupt and will print another message if that fails.

Accordingly, lower the priority of this message to INFO priority, since
it does not reflect any sort of loss of functionality, but rather just a
limitation of the configuration of the runtime system.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 drivers/net/e1000/e1000_main.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 637ae8f..089ae3f 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -307,7 +307,7 @@ static int e1000_request_irq(struct e1000_adapter *adapter)
 	if (adapter->hw.mac_type >= e1000_82571) {
 		adapter->have_msi = TRUE;
 		if ((err = pci_enable_msi(adapter->pdev))) {
-			DPRINTK(PROBE, ERR,
+			DPRINTK(PROBE, INFO,
 			 "Unable to allocate MSI interrupt Error: %d\n", err);
 			adapter->have_msi = FALSE;
 		}
-- 
1.5.1.4

Re: [PATCH] [e1000] Lower the MSI unavailable message to INFO priority

[Jeff Garzik]

H. Peter Anvin wrote:
> diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
> index 637ae8f..089ae3f 100644
> --- a/drivers/net/e1000/e1000_main.c
> +++ b/drivers/net/e1000/e1000_main.c
> @@ -307,7 +307,7 @@ static int e1000_request_irq(struct e1000_adapter *adapter)
>  	if (adapter->hw.mac_type >= e1000_82571) {
>  		adapter->have_msi = TRUE;
>  		if ((err = pci_enable_msi(adapter->pdev))) {
> -			DPRINTK(PROBE, ERR,
> +			DPRINTK(PROBE, INFO,
>  			 "Unable to allocate MSI interrupt Error: %d\n", err);
>  			adapter->have_msi = FALSE;


Actually, it should not print any message at all.

pci_enable_msi() failure is a normal event (as you point out).  Even at 
KERN_INFO level, the message is still misleading.

	Jeff



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Re: [PATCH] [e1000] Lower the MSI unavailable message to INFO priority

[Kok, Auke]

Jeff Garzik wrote:
> H. Peter Anvin wrote:
>> diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
>> index 637ae8f..089ae3f 100644
>> --- a/drivers/net/e1000/e1000_main.c
>> +++ b/drivers/net/e1000/e1000_main.c
>> @@ -307,7 +307,7 @@ static int e1000_request_irq(struct e1000_adapter *adapter)
>>  	if (adapter->hw.mac_type >= e1000_82571) {
>>  		adapter->have_msi = TRUE;
>>  		if ((err = pci_enable_msi(adapter->pdev))) {
>> -			DPRINTK(PROBE, ERR,
>> +			DPRINTK(PROBE, INFO,
>>  			 "Unable to allocate MSI interrupt Error: %d\n", err);
>>  			adapter->have_msi = FALSE;
> 
> 
> Actually, it should not print any message at all.
> 
> pci_enable_msi() failure is a normal event (as you point out).  Even at 
> KERN_INFO level, the message is still misleading.

I've been reworking some of this code and there is even a pci_disable_msi() 
missing in case pci_request_irq failed. I'll post a patch to clean it up in a 
second.

Cheers,

Auke

Re: [PATCH] [e1000] Lower the MSI unavailable message to INFO priority

[Chuck Ebbert]

Kok, Auke wrote:
> Jeff Garzik wrote:
>> H. Peter Anvin wrote:
>>> diff --git a/drivers/net/e1000/e1000_main.c
>>> b/drivers/net/e1000/e1000_main.c
>>> index 637ae8f..089ae3f 100644
>>> --- a/drivers/net/e1000/e1000_main.c
>>> +++ b/drivers/net/e1000/e1000_main.c
>>> @@ -307,7 +307,7 @@ static int e1000_request_irq(struct e1000_adapter
>>> *adapter)
>>>      if (adapter->hw.mac_type >= e1000_82571) {
>>>          adapter->have_msi = TRUE;
>>>          if ((err = pci_enable_msi(adapter->pdev))) {
>>> -            DPRINTK(PROBE, ERR,
>>> +            DPRINTK(PROBE, INFO,
>>>               "Unable to allocate MSI interrupt Error: %d\n", err);
>>>              adapter->have_msi = FALSE;
>>
>>
>> Actually, it should not print any message at all.
>>
>> pci_enable_msi() failure is a normal event (as you point out).  Even
>> at KERN_INFO level, the message is still misleading.
> 
> I've been reworking some of this code and there is even a
> pci_disable_msi() missing in case pci_request_irq failed. I'll post a
> patch to clean it up in a second.

It seems ixgb needs this too (the message removal at least?)



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Re: [PATCH] [e1000] Lower the MSI unavailable message to INFO priority

[Kok, Auke]

Chuck Ebbert wrote:
> Kok, Auke wrote:
>> Jeff Garzik wrote:
>>> H. Peter Anvin wrote:
>>>> diff --git a/drivers/net/e1000/e1000_main.c
>>>> b/drivers/net/e1000/e1000_main.c
>>>> index 637ae8f..089ae3f 100644
>>>> --- a/drivers/net/e1000/e1000_main.c
>>>> +++ b/drivers/net/e1000/e1000_main.c
>>>> @@ -307,7 +307,7 @@ static int e1000_request_irq(struct e1000_adapter
>>>> *adapter)
>>>>      if (adapter->hw.mac_type >= e1000_82571) {
>>>>          adapter->have_msi = TRUE;
>>>>          if ((err = pci_enable_msi(adapter->pdev))) {
>>>> -            DPRINTK(PROBE, ERR,
>>>> +            DPRINTK(PROBE, INFO,
>>>>               "Unable to allocate MSI interrupt Error: %d\n", err);
>>>>              adapter->have_msi = FALSE;
>>>
>>> Actually, it should not print any message at all.
>>>
>>> pci_enable_msi() failure is a normal event (as you point out).  Even
>>> at KERN_INFO level, the message is still misleading.
>> I've been reworking some of this code and there is even a
>> pci_disable_msi() missing in case pci_request_irq failed. I'll post a
>> patch to clean it up in a second.
> 
> It seems ixgb needs this too (the message removal at least?)

yes, I'll get there once I get a chance to get some e1000 work near completion 
first. I don't think that for ixgb this is as big of a deal for now. If MSI is 
breaking with a 10gig adapter I think people appreciate the error.

We do have to make sure that the PCI subsystem throws errors in the case it is 
justified, like when we're out of vectors, or something really bad happens 
(perhaps suspend/resumish). I assume that is the case, but I haven't checked.

Cheers,

Auke

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Re: [PATCH] [e1000] Lower the MSI unavailable message to INFO priority

[Jeff Garzik]

Kok, Auke wrote:
> for now. If MSI is breaking with a 10gig adapter I think people 
> appreciate the error.


No, that is same invalid reasoning discussed earlier in this thread. 
ixgb needs patching for this problem too.

	Jeff

Re: [PATCH] [e1000] Lower the MSI unavailable message to INFO priority

[Kok, Auke]

Jeff Garzik wrote:
> Kok, Auke wrote:
>> for now. If MSI is breaking with a 10gig adapter I think people 
>> appreciate the error.
> 
> 
> No, that is same invalid reasoning discussed earlier in this thread. 
> ixgb needs patching for this problem too.

OK then... A patch that does the exact same for ixgb as I did for e1000 is 
underway (remove #ifdef CONFIG_PCI_MSI, fix pci_disable_msi leak...).

Cheers,

Auke