From cfc2d4c5151bb8449fd28b2591877a514214ad4a Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Tue, 30 Apr 2024 11:43:51 +0530 Subject: PCI: endpoint: pci-epf-test: Handle Link Down event MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Per PCIe r6.0, sec 5.2, a Link Down event can happen under any of the following circumstances: 1. Fundamental/Hot reset 2. Link disable transmission by upstream component 3. Moving from L2/L3 to L0 When the event happens, the EPC driver capable of detecting it may pass the notification to the EPF driver through link_down() callback in 'struct pci_epc_event_ops'. While the PCIe spec has not defined the actual behavior of the endpoint when the Link Down event happens, we may assume that at least the ongoing transactions need to be stopped as the link won't be active, so cancel the command handler work in the callback implementation pci_epf_test_link_down(). The work will be started again in pci_epf_test_link_up() once the link comes back again. Link: https://lore.kernel.org/linux-pci/20240430-pci-epf-rework-v4-10-22832d0d456f@linaro.org Tested-by: Niklas Cassel Signed-off-by: Manivannan Sadhasivam Signed-off-by: Krzysztof Wilczyński [bhelgaas: update spec citation] Signed-off-by: Bjorn Helgaas Reviewed-by: Niklas Cassel --- drivers/pci/endpoint/functions/pci-epf-test.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 447071aa359f..e771be7512a1 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -792,9 +792,19 @@ static int pci_epf_test_link_up(struct pci_epf *epf) return 0; } +static int pci_epf_test_link_down(struct pci_epf *epf) +{ + struct pci_epf_test *epf_test = epf_get_drvdata(epf); + + cancel_delayed_work_sync(&epf_test->cmd_handler); + + return 0; +} + static const struct pci_epc_event_ops pci_epf_test_event_ops = { .epc_init = pci_epf_test_epc_init, .link_up = pci_epf_test_link_up, + .link_down = pci_epf_test_link_down, }; static int pci_epf_test_alloc_space(struct pci_epf *epf) -- cgit v1.2.3