Re: [PATCH 1/3] selftests: pci_endpoint: Skip subrange map test if iATU allocation fails

[Christian Bruel <christian.bruel@foss.st.com>]

On 3/20/26 15:05, Koichiro Den wrote:
> On Fri, Mar 20, 2026 at 11:04:28AM +0100, Christian Bruel wrote:
>> Hello Koichiro, thank you for your comment
>>
>> On 3/19/26 02:28, Koichiro Den wrote:
>>> On Wed, Mar 18, 2026 at 03:46:27PM +0100, Christian Bruel wrote:
>>>> Handle -ENOSPC error. If the number of available inbound ATU entries is
>>>> insufficient to map the subrange, skip the test instead of failing.
>>>>
>>>> Link: https://lore.kernel.org/linux-pci/20260317152707.GA85951@bhelgaas/T/#m87e4c24173097a0ea70195b71aab294ad8d6c283
>>>> Signed-off-by: Christian Bruel <christian.bruel@foss.st.com>
>>>> ---
>>>>    tools/testing/selftests/pci_endpoint/pci_endpoint_test.c | 2 ++
>>>>    1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/tools/testing/selftests/pci_endpoint/pci_endpoint_test.c b/tools/testing/selftests/pci_endpoint/pci_endpoint_test.c
>>>> index c417fb3a198b2d92c3060938c23807cc8bea5573..8ea2fda4539d11eb22b22800a7cb8bbaa99c91ba 100644
>>>> --- a/tools/testing/selftests/pci_endpoint/pci_endpoint_test.c
>>>> +++ b/tools/testing/selftests/pci_endpoint/pci_endpoint_test.c
>>>> @@ -88,6 +88,8 @@ TEST_F(pci_ep_bar, BAR_SUBRANGE_TEST)
>>>>    		SKIP(return, "Subrange map is not supported");
>>>>    	if (ret == -ENOBUFS)
>>>>    		SKIP(return, "BAR is reserved");
>>>> +	if (ret == -ENOSPC)
>>>> +		SKIP(return, "Not enough ATU entries to allocate subrange");
>>>
>>> Thank you for handling this!
>>>
>>> pci_endpoint_test_bar_subrange() can also return -ENOSPC locally:
>>> https://github.com/torvalds/linux/blob/v7.0-rc4/drivers/misc/pci_endpoint_test.c#L538
>>> While that is a different resource limit case, I think it would still be
>>> reasonable to treat it as SKIP as well.
>>
>> Regarding Niklas's feedback to use the local EINVAL instead of ENOSPC in
>> pci_endpoint_test_bar_subrange(), I prefer to leave this for you to handle.
>> That will cover this case.
> 
> So could you consider the following tiny patch as a prerequisite for your
> series?
> https://lore.kernel.org/linux-pci/20260320140139.2415480-1-den@valinux.co.jp/

sure, thank you

> 
>>
>>>
>>> If you agree and keep your current approach, then I think the SKIP message
>>> might be better phrased more generically, e.g. "Insufficient resources".
>>
>> OK I agree, the error message should be less specific to DWC terminology,
>> even though this case can currently only occur on it.
> 
> Yes, I agree. As mentioned in my reply to Niklas, the other -ENOSPC is better
> replaced with -EINVAL, so I just submitted a tiny patch. That concern should be
> resolved.
> 
>>
>>>
>>> If you prefer to keep that local case as FAIL (or at least distinguish it
>>> with a different SKIP message), that would likely require a bit more
>>> changes overall. Note: Niklas' earlier feedback on the SKIP message would
>>> still apply.
>>
>> OK, as Niklas also suggested, I will not set an additional local bit besides
>> the fail bit. The question is whether we should name it SKIP or NOSPC. I
>> slightly prefer NOSPC, as this is what is used in the selftest to indicate
>> skipping.
> 
> Personally, Niklas' "errno in struct pci_epf_test_reg" idea sounds the best
> among the options discussed so far.

It is a good solution but does not match very well with the other 
existing API (See the STATUS_SRC/DST_ADDR_INVALID bits). Thus, we will 
keep the existing method of reporting errors using a second bit 
alongside the FAIL bit.


> 
> Best regards,
> Koichiro
> 
>>
>> thank you
>>
>> Christian
>>
>>>
>>> Best regards,
>>> Koichiro
>>>
>>>>    	EXPECT_FALSE(ret) TH_LOG("Test failed for BAR%d", variant->barno);
>>>>    }
>>>>
>>>> -- 
>>>> 2.34.1
>>>>
>>