Re: common_interrupt: No irq handler for vector

[Shuah Khan <skhan@linuxfoundation.org>]

On 12/14/20 1:41 PM, Thomas Gleixner wrote:
> On Mon, Dec 14 2020 at 09:11, Shuah Khan wrote:
>> On 12/12/20 12:33 PM, Thomas Gleixner wrote:
>>> On Fri, Dec 11 2020 at 13:41, Shuah Khan wrote:
>>>
>>>> I am debugging __common_interrupt: 1.55 No irq handler for vector
>>>> messages and noticed comments and code don't agree:
>>>
>>> I bet that's on an AMD system with broken AGESA BIOS.... Good luck
>>> debugging it :) BIOS updates are on the way so I'm told.
>>>
>> Interesting. The behavior I am seeing doesn't seem to be consistent
>> with BIOS problem. I don't see these messages on 5.10-rc7. I started
>> seeing them on stable releases. It started right around 5.9.9 and
>> not present on 5.9.7.
> 
> What kind of machine?

Here is the processor and BIOS info:
AMD Ryzen 7 4700G with Radeon Graphics
LENOVO ThinkCentre Embedded Controller -[O4ZCT12A-1.12]-
LENOVO ThinkCentre BIOS Boot Block Revision 1.1C

> 
>> I am bisecting to isolate. Same issue on all stables 5.4, 4.19 and
>> so on. If it is BIOS problem I would expect to see it on 5.10-rc7
>> and wouldn't have expected to start seeing it 5.9.9.
> 
> Can you provide some more details, e.g. dmesg please?
> 

__common_interrupt: 1.55 No irq handler for vector
__common_interrupt: 2.55 No irq handler for vector
__common_interrupt: 3.55 No irq handler for vector
__common_interrupt: 4.55 No irq handler for vector
__common_interrupt: 5.55 No irq handler for vector
__common_interrupt: 6.55 No irq handler for vector
__common_interrupt: 7.55 No irq handler for vector
__common_interrupt: 8.55 No irq handler for vector
__common_interrupt: 9.55 No irq handler for vector
__common_interrupt: 10.55 No irq handler for vector

>>> No. It's perfectly correct in the MSI code. See further down.
>>>
>>> 	if (IS_ERR_OR_NULL(this_cpu_read(vector_irq[cfg->vector])))
>>> 		this_cpu_write(vector_irq[cfg->vector], VECTOR_RETRIGGERED);
>>>
>>
>> I am asking about inconsistent comments and the actual message as the
>> comment implies if vector is VECTOR_UNUSED state, this message won't
>> be triggered in common_interrupt. Based on that my read is the comment
>> might be wrong if the code is correct as you are saying.
> 
> The comment says:
> 
>    >>    * anyway. If the vector is unused, then it is marked so it won't
>    >>    * trigger the 'No irq handler for vector' warning in
>    >>    * common_interrupt().
> 
>    If the vector is unused, then it is _marked_ so ....

See the messages above.

> 
> It perhaps should explicitely say 'is marked as VECTOR_RETRIGGERED' to make
> it clear.
> 

Possibly. I am running bisect starting at v5.9.7 (good) and compare with
v5.9.13 and see why this problems started showing up.

thanks,
-- Shuah