From 8d3bf19f1b585a3cc0027f508b64c33484db8d0d Mon Sep 17 00:00:00 2001 From: Krishna chaitanya chundru Date: Sat, 23 Nov 2024 00:39:59 +0530 Subject: [PATCH] PCI: dwc: Don't wait for link up if driver can detect Link Up event MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit If the driver can detect the Link Up event and enumerate downstream devices at that time, we need not wait here. Skip waiting for link to come up if the driver supports 'use_linkup_irq'. Link: https://lore.kernel.org/r/20241123-remove_wait2-v5-1-b5f9e6b794c2@quicinc.com Signed-off-by: Krishna chaitanya chundru Signed-off-by: Krzysztof Wilczyński [bhelgaas: wrap comment, update commit log] Signed-off-by: Bjorn Helgaas Reviewed-by: Manivannan Sadhasivam Reviewed-by: Niklas Cassel --- drivers/pci/controller/dwc/pcie-designware-host.c | 10 ++++++++-- drivers/pci/controller/dwc/pcie-designware.h | 1 + 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index d2291c3ceb8be..bcbbe02f8f86f 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -530,8 +530,14 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp) goto err_remove_edma; } - /* Ignore errors, the link may come up later */ - dw_pcie_wait_for_link(pci); + /* + * Note: Skip the link up delay only when a Link Up IRQ is present. + * If there is no Link Up IRQ, we should not bypass the delay + * because that would require users to manually rescan for devices. + */ + if (!pp->use_linkup_irq) + /* Ignore errors, the link may come up later */ + dw_pcie_wait_for_link(pci); bridge->sysdata = pp; diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 347ab74ac35aa..1d0ec47e1986a 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -379,6 +379,7 @@ struct dw_pcie_rp { bool use_atu_msg; int msg_atu_index; struct resource *msg_res; + bool use_linkup_irq; }; struct dw_pcie_ep_ops { -- 2.39.5