Re: [PATCH] PCI: endpoint: pci-epf-test: Roll back BAR mapping when subrange setup fails

Christian Bruel
2026-03-17T10:02:28Z

On 3/17/26 10:59, Manivannan Sadhasivam wrote:
> On Tue, Mar 17, 2026 at 10:13:52AM +0100, Christian Bruel wrote:
>>
>>
>> On 3/17/26 03:57, Koichiro Den wrote:
>>> On Mon, Mar 16, 2026 at 05:19:26PM +0100, Niklas Cassel wrote:
>>>> On Mon, Mar 16, 2026 at 11:02:25PM +0900, Koichiro Den wrote:
>>>>> When the BAR subrange mapping test on DWC-based platforms fails due to
>>>>> insufficient free inbound iATU regions,
>>>>> pci_epf_test_bar_subrange_setup() returns an error (-ENOSPC) but does
>>>>> not restore the original BAR mapping. This causes subsequent test runs
>>>>> to become confusing, since the failure may leave room for the next
>>>>> subrange mapping test to pass.
>>>>>
>>>>> Fix this by restoring the original BAR mapping when preparation of the
>>>>> subrange mapping fails, so that no side effect remains regardless of the
>>>>> test success or failure.
>>>>>
>>>>> Fixes: 6c5e6101423b ("PCI: endpoint: pci-epf-test: Add BAR subrange mapping test support")
>>>>> Reported-by: Christian Bruel <christian.bruel@foss.st.com>
>>>>> Closes: https://lore.kernel.org/linux-pci/b2b03ebe-9482-4a13-b22f-7b44da096eed@foss.st.com/
>>>>> Signed-off-by: Koichiro Den <den@valinux.co.jp>
>>>>> ---
>>>>> drivers/pci/endpoint/functions/pci-epf-test.c | 6 ++++++
>>>>> 1 file changed, 6 insertions(+)
>>>>>
>>>>> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
>>>>> index 14e61ebe1f11..f44c36f5cac5 100644
>>>>> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
>>>>> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
>>>>> @@ -898,16 +898,22 @@ static void pci_epf_test_bar_subrange_setup(struct pci_epf_test *epf_test,
>>>>> bar->submap = submap;
>>>>> bar->num_submap = nsub;
>>>>> ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no, bar);
>>>>> if (ret) {
>>>>> dev_err(&epf->dev, "pci_epc_set_bar() failed: %d\n", ret);
>>>>> bar->submap = old_submap;
>>>>> bar->num_submap = old_nsub;
>>>>> + ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no, bar);
>>>>> + if (ret)
>>>>> + dev_warn(&epf->dev,
>>>>> + "failed to restore the original BAR mapping: %d\n",
>>>>
>>>> Nit:
>>>> I would use a capitalized F:
>>>> "Failed to restore ..."
>>>>
>>>> in order to match most other prints in this file.
>>>
>>> Agree. Bjorn or Mani, please feel free to fix this up (i.e. s/failed/Failed/)
>>> when applying, to avoid a respin for such a minor change.
>>>
>>>>
>>>> Reviewed-by: Niklas Cassel <cassel@kernel.org>
>>>
>>> Thanks again for reviewing, Niklas.
>>>
>>> Christian, if possible, it would be very helpful if you could take a look or
>>> test this slightly polished version and add a Tested-by or Reviewed-by.
>>
>> Tested-by: Christian Bruel <christian.bruel@foss.st.com>
>>
>> with the DISABLE BAR dependency
>> https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/commit/?h=endpoint&id=33642e9e36dc084e4fc9245a266c9843bc8303b9
>>
>
> Why is this dependency?

no not needed, sorry. will be handler in the stm32 part.

>
> - Mani
>