[PATCH v6 2/3] PCI: dwc: Force L2 link entry on shutdown/reboot without D3cold check
From: Krishna Chaitanya Chundru
Date: Wed Sep 09 2026 - 08:35:47 EST
dw_pcie_suspend_noirq() normally calls pci_host_common_d3cold_possible()
to check whether every downstream endpoint can be put into D3cold before
bothering to move the link to L2. If no endpoint supports it, the
function returns early and leaves the link up.
Querying D3cold support during shutdown is actively harmful, not just
slow: pci_host_common_d3cold_possible() requires every active endpoint
to already be in PCI_D3hot, and returns false otherwise. If any endpoint
is still in D0 -- which is common, since endpoint drivers aren't
guaranteed to have suspended by the time the host's shutdown path runs
the check fails and dw_pcie_suspend_noirq() returns early without ever
moving the link to L2, leaving it up right up to the point where the
system cuts power/clocks to the controller.
Add a force parameter to dw_pcie_suspend_noirq() that callers set
explicitly to force this behavior, still call
pci_host_common_d3cold_possible() unconditionally, since it's also how
pme_capable gets set, but ignore its return value and force L2 entry
regardless when force is set.
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@xxxxxxxxxxxxxxxx>
---
drivers/pci/controller/dwc/pci-imx6.c | 2 +-
drivers/pci/controller/dwc/pci-layerscape.c | 2 +-
drivers/pci/controller/dwc/pcie-designware-host.c | 7 ++++---
drivers/pci/controller/dwc/pcie-designware.h | 4 ++--
drivers/pci/controller/dwc/pcie-eswin.c | 2 +-
drivers/pci/controller/dwc/pcie-nxp-s32g.c | 2 +-
drivers/pci/controller/dwc/pcie-qcom.c | 2 +-
drivers/pci/controller/dwc/pcie-stm32.c | 2 +-
drivers/pci/controller/dwc/pcie-ultrarisc.c | 2 +-
9 files changed, 13 insertions(+), 12 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 4105c28d180c..63799b1c2013 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1738,7 +1738,7 @@ static int imx_pcie_suspend_noirq(struct device *dev)
imx_pcie_assert_perst(imx_pcie, true);
imx_pcie->drvdata->enable_ref_clk(imx_pcie, false);
} else {
- return dw_pcie_suspend_noirq(imx_pcie->pci);
+ return dw_pcie_suspend_noirq(imx_pcie->pci, false);
}
return 0;
diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c
index 14d6ac4fc53f..aca1b0acb4ed 100644
--- a/drivers/pci/controller/dwc/pci-layerscape.c
+++ b/drivers/pci/controller/dwc/pci-layerscape.c
@@ -382,7 +382,7 @@ static int ls_pcie_suspend_noirq(struct device *dev)
if (!pcie->drvdata->pm_support)
return 0;
- return dw_pcie_suspend_noirq(pcie->pci);
+ return dw_pcie_suspend_noirq(pcie->pci, false);
}
static int ls_pcie_resume_noirq(struct device *dev)
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index f5a38e6fd8d7..21830c05d147 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -1222,16 +1222,17 @@ static int dw_pcie_pme_turn_off(struct dw_pcie *pci)
return 0;
}
-int dw_pcie_suspend_noirq(struct dw_pcie *pci)
+int dw_pcie_suspend_noirq(struct dw_pcie *pci, bool force)
{
- bool pme_capable = false;
+ bool d3cold_possible, pme_capable = false;
int ret = 0;
u32 val;
if (!dw_pcie_link_up(pci))
goto stop_link;
- if (!pci_host_common_d3cold_possible(pci->pp.bridge, &pme_capable))
+ d3cold_possible = pci_host_common_d3cold_possible(pci->pp.bridge, &pme_capable);
+ if (!d3cold_possible && !force)
return 0;
if (pci->pp.ops->pme_turn_off) {
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index a53ac27cd244..cec1c64c3a5e 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -860,7 +860,7 @@ static inline enum dw_pcie_ltssm dw_pcie_get_ltssm(struct dw_pcie *pci)
const char *dw_pcie_ltssm_status_string(enum dw_pcie_ltssm ltssm);
#ifdef CONFIG_PCIE_DW_HOST
-int dw_pcie_suspend_noirq(struct dw_pcie *pci);
+int dw_pcie_suspend_noirq(struct dw_pcie *pci, bool force);
int dw_pcie_resume_noirq(struct dw_pcie *pci);
void dw_handle_msi_irq(struct dw_pcie_rp *pp);
void dw_pcie_msi_init(struct dw_pcie_rp *pp);
@@ -873,7 +873,7 @@ int dw_pcie_allocate_domains(struct dw_pcie_rp *pp);
void __iomem *dw_pcie_own_conf_map_bus(struct pci_bus *bus, unsigned int devfn,
int where);
#else
-static inline int dw_pcie_suspend_noirq(struct dw_pcie *pci)
+static inline int dw_pcie_suspend_noirq(struct dw_pcie *pci, bool force)
{
return 0;
}
diff --git a/drivers/pci/controller/dwc/pcie-eswin.c b/drivers/pci/controller/dwc/pcie-eswin.c
index ce8d64f8a395..06fc488f80c7 100644
--- a/drivers/pci/controller/dwc/pcie-eswin.c
+++ b/drivers/pci/controller/dwc/pcie-eswin.c
@@ -367,7 +367,7 @@ static int eswin_pcie_suspend_noirq(struct device *dev)
{
struct eswin_pcie *pcie = dev_get_drvdata(dev);
- return dw_pcie_suspend_noirq(&pcie->pci);
+ return dw_pcie_suspend_noirq(&pcie->pci, false);
}
static int eswin_pcie_resume_noirq(struct device *dev)
diff --git a/drivers/pci/controller/dwc/pcie-nxp-s32g.c b/drivers/pci/controller/dwc/pcie-nxp-s32g.c
index 31e1169b8ab6..43174a06c60a 100644
--- a/drivers/pci/controller/dwc/pcie-nxp-s32g.c
+++ b/drivers/pci/controller/dwc/pcie-nxp-s32g.c
@@ -365,7 +365,7 @@ static int s32g_pcie_suspend_noirq(struct device *dev)
struct s32g_pcie *s32g_pp = dev_get_drvdata(dev);
struct dw_pcie *pci = &s32g_pp->pci;
- return dw_pcie_suspend_noirq(pci);
+ return dw_pcie_suspend_noirq(pci, false);
}
static int s32g_pcie_resume_noirq(struct device *dev)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index ee63a6ec99de..2693a98d0b27 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -2421,7 +2421,7 @@ static int qcom_pcie_suspend_noirq(struct device *dev)
if (!pcie)
return 0;
- ret = dw_pcie_suspend_noirq(pcie->pci);
+ ret = dw_pcie_suspend_noirq(pcie->pci, false);
if (ret)
return ret;
diff --git a/drivers/pci/controller/dwc/pcie-stm32.c b/drivers/pci/controller/dwc/pcie-stm32.c
index 349618ea5b9c..7b3a8c1b04a4 100644
--- a/drivers/pci/controller/dwc/pcie-stm32.c
+++ b/drivers/pci/controller/dwc/pcie-stm32.c
@@ -78,7 +78,7 @@ static int stm32_pcie_suspend_noirq(struct device *dev)
struct stm32_pcie *stm32_pcie = dev_get_drvdata(dev);
int ret;
- ret = dw_pcie_suspend_noirq(&stm32_pcie->pci);
+ ret = dw_pcie_suspend_noirq(&stm32_pcie->pci, false);
if (ret)
return ret;
diff --git a/drivers/pci/controller/dwc/pcie-ultrarisc.c b/drivers/pci/controller/dwc/pcie-ultrarisc.c
index 51e89180490d..cb2781a1557f 100644
--- a/drivers/pci/controller/dwc/pcie-ultrarisc.c
+++ b/drivers/pci/controller/dwc/pcie-ultrarisc.c
@@ -187,7 +187,7 @@ static int ultrarisc_pcie_suspend_noirq(struct device *dev)
if (pci->suspended)
return 0;
- ret = dw_pcie_suspend_noirq(pci);
+ ret = dw_pcie_suspend_noirq(pci, false);
if (ret)
return ret;
--
2.34.1