From b3172ec3ab2d2755b188bbf8ef2050f5d5efa27b Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Mon, 8 Sep 2025 18:19:42 +0200 Subject: [PATCH] PCI: endpoint: pci-epf-test: Fix doorbell test support [ Upstream commit f272210b28d050df56ec7dfaecb9fa3bebca6419 ] The doorbell feature temporarily overrides the inbound translation to point to the address stored in epf_test->db_bar.phys_addr, i.e., it calls set_bar() twice without ever calling clear_bar(), as calling clear_bar() would clear the BAR's PCI address assigned by the host. Thus, when disabling the doorbell, restore the inbound translation to point to the memory allocated for the BAR. Without this, running the PCI endpoint kselftest doorbell test case more than once would fail. Fixes: eff0c286aa91 ("PCI: endpoint: pci-epf-test: Add doorbell test support") Signed-off-by: Niklas Cassel Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Reviewed-by: Frank Li Link: https://patch.msgid.link/20250908161942.534799-2-cassel@kernel.org Signed-off-by: Sasha Levin --- drivers/pci/endpoint/functions/pci-epf-test.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index e091193bd8a8..2a85d3eda92f 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -772,12 +772,24 @@ static void pci_epf_test_disable_doorbell(struct pci_epf_test *epf_test, u32 status = le32_to_cpu(reg->status); struct pci_epf *epf = epf_test->epf; struct pci_epc *epc = epf->epc; + int ret; if (bar < BAR_0) goto set_status_err; pci_epf_test_doorbell_cleanup(epf_test); - pci_epc_clear_bar(epc, epf->func_no, epf->vfunc_no, &epf_test->db_bar); + + /* + * The doorbell feature temporarily overrides the inbound translation + * to point to the address stored in epf_test->db_bar.phys_addr, i.e., + * it calls set_bar() twice without ever calling clear_bar(), as + * calling clear_bar() would clear the BAR's PCI address assigned by + * the host. Thus, when disabling the doorbell, restore the inbound + * translation to point to the memory allocated for the BAR. + */ + ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no, &epf->bar[bar]); + if (ret) + goto set_status_err; status |= STATUS_DOORBELL_DISABLE_SUCCESS; reg->status = cpu_to_le32(status);