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;
Kind regards,
Niklas
