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

[Christian Bruel]

On 3/17/26 11:12, Niklas Cassel wrote:
> On Tue, Mar 17, 2026 at 11:01:28AM +0100, Christian Bruel wrote:
> > > So we will need to add a SKIP ENOSPC case in TEST_F(pci_ep_bar,
> > > BAR_SUBRANGE_TEST)
> > Re-checking this, no need for ENOSPC test. The real condition would be
> > EBUSY. Which can be handled nicely in a stm32 ep_map_addr helper.
>
> Are you sure that it returns EBUSY and not ENOSPC?
>
> I would have expected the error to be ENOSPC when there are no free inbound
> window:
> https://github.com/torvalds/linux/blob/v7.0-rc4/drivers/pci/controller/dwc/pcie-designware-ep.c#L307-L312

dw_pcie_ep_ib_atu_addr() returns ENOSPC. I was thinking to overload 
.set_bar with a stm32 helper to return EBUSY if the subrange bar is 
already reserved.

So whatever is best
 - modify TEST_F to SKIP if ENOSPC
or
 - Add a specific platform .set_bar helper to return EBUSY, already 
handled in the test.

thank you

Christian

> I think a SKIP ENOSPC case in TEST_F(pci_ep_bar, BAR_SUBRANGE_TEST) in
> a better solution than modifying a STM32 specific helper.
>
> Because the former will ensure that we skip/handle this issue on all SoCs
> with few inbound windows, not only on STM32.
>
>
> Kind regards,
> Niklas