On Tue, Feb 10, 2026 at 05:38:19PM +0100, Niklas Cassel wrote:
> On Tue, Feb 10, 2026 at 10:54:20PM +0900, Koichiro Den wrote:
> > On Tue, Feb 10, 2026 at 01:36:29PM +0100, Niklas Cassel wrote:
> > > On Mon, Feb 09, 2026 at 09:53:14PM +0900, Koichiro Den wrote:
> > > > pci_epf_test_enable_doorbell() allocates a doorbell and then installs
> > > > the interrupt handler with request_threaded_irq(). On failures before
> > > > the IRQ is successfully requested (e.g. no free BAR,
> > > > request_threaded_irq() failure), the error path jumps to
> > > > err_doorbell_cleanup and calls pci_epf_test_doorbell_cleanup().
> > > >
> > > > pci_epf_test_doorbell_cleanup() unconditionally calls free_irq() for the
> > > > doorbell virq, which can trigger "Trying to free already-free IRQ"
> > > > warnings when the IRQ was never requested.
> > > >
> > > > Track whether the doorbell IRQ has been successfully requested and only
> > > > call free_irq() when it has.
> > > >
> > > > Fixes: eff0c286aa91 ("PCI: endpoint: pci-epf-test: Add doorbell test
> > > > support")
> > > > Signed-off-by: Koichiro Den <[email protected]>
> > > > ---
> > > > drivers/pci/endpoint/functions/pci-epf-test.c | 9 ++++++++-
> > > > 1 file changed, 8 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c
> > > > b/drivers/pci/endpoint/functions/pci-epf-test.c
> > > > index 6952ee418622..23034f548c90 100644
> > > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> > > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> > > > @@ -86,6 +86,7 @@ struct pci_epf_test {
> > > > bool dma_private;
> > > > const struct pci_epc_features *epc_features;
> > > > struct pci_epf_bar db_bar;
> > > > + bool db_irq_requested;
> > > > size_t bar_size[PCI_STD_NUM_BARS];
> > > > };
> > > >
> > > > @@ -715,7 +716,10 @@ static void pci_epf_test_doorbell_cleanup(struct
> > > > pci_epf_test *epf_test)
> > > > struct pci_epf_test_reg *reg =
> > > > epf_test->reg[epf_test->test_reg_bar];
> > > > struct pci_epf *epf = epf_test->epf;
> > > >
> > > > - free_irq(epf->db_msg[0].virq, epf_test);
> > > > + if (epf_test->db_irq_requested && epf->db_msg) {
> > > > + free_irq(epf->db_msg[0].virq, epf_test);
> > > > + epf_test->db_irq_requested = false;
> > > > + }
> > > > reg->doorbell_bar = cpu_to_le32(NO_BAR);
> > > >
> > > > pci_epf_free_doorbell(epf);
> > > > @@ -741,6 +745,8 @@ static void pci_epf_test_enable_doorbell(struct
> > > > pci_epf_test *epf_test,
> > > > if (bar < BAR_0)
> > > > goto err_doorbell_cleanup;
> > > >
> > > > + epf_test->db_irq_requested = false;
> > > > +
> > > > ret = request_threaded_irq(epf->db_msg[0].virq, NULL,
> > > > pci_epf_test_doorbell_handler,
> > > > IRQF_ONESHOT,
> > > > "pci-ep-test-doorbell", epf_test);
> > >
> > > Another bug in pci_epf_test_enable_doorbell():
> > >
> > > Since we reuse the BAR size, and use dynamic inbound mapping,
> > > what if the returned DB offset is larger than epf->bar[bar].size ?
> > >
> > > I think we need something like this before calling pci_epc_set_bar():
> > >
> > > if (reg->doorbell_offset >= epf->bar[bar].size)
> > > goto err_doorbell_cleanup;
> >
> > Right, I remember this coming up in another thread.
> >
> > If there are no objections from either of you, I'm happy to include a fix
> > patch for this in v7.
>
> No objection from me.
>
>
> Ideally I would also like:
>
> if (!(test->ep_caps & CAP_DYNAMIC_INBOUND_MAPPING))
> return -EOPNOTSUPP;
>
> and that the pci_endpoint_test selftest would return skip on -EOPNOTSUPP,
> since the doorbell test currently relies on CAP_DYNAMIC_INBOUND_MAPPING,
> but that might make your series too big.
That makes sense. I'll consider posting a stand-alone patch for that
separately.
Best regards,
Koichiro
>
>
> Thus, I'm happy if you add a safety check for:
> reg->doorbell_offset >= epf->bar[bar].size
>
>
> Kind regards,
> Niklas
>
