From: Richard Zhu <hongxing.zhu@nxp.com>
To: frank.li@nxp.com, hongxing.zhu@nxp.com
Cc: imx@lists.linux.dev
Subject: [PATCH v2] PCI: dwc: Fix suspend hang when e1000e network card is connected
Date: Tue, 14 May 2024 13:56:38 +0800 [thread overview]
Message-ID: <1715666198-9140-1-git-send-email-hongxing.zhu@nxp.com> (raw)
In dw_pcie_suspend_noirq() and after the PME_TURN_OFF messgage is sent out,
one PMC version2.0 endpoint device E1000E network card hangs in LTSSM stat
polling and L2 stat check.
To avoid this hang issue after the PME_TURN_OFF message is sent out.
Only poll and check LTSSM L2 stat if the EP's PMC version is 3 or later,
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
- Add a new help function dwc_get_devices_pmc_version() to get devices PMC
versions.
.../pci/controller/dwc/pcie-designware-host.c | 46 ++++++++++++++++++-
1 file changed, 45 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index cb8c3c2bcc790..0c2794e7bcf0a 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -884,6 +884,42 @@ int dw_pcie_setup_rc(struct dw_pcie_rp *pp)
}
EXPORT_SYMBOL_GPL(dw_pcie_setup_rc);
+static int dwc_get_devices_pmc_version(struct dw_pcie *pci)
+{
+ int ret;
+ u16 pmc, ver = 0;
+ struct dw_pcie_rp *pp = &pci->pp;
+ struct pci_bus *child, *root_bus = NULL;
+ struct pci_dev *pdev;
+
+ /* Check the remote EP's PMC version */
+ list_for_each_entry(child, &pp->bridge->bus->children, node) {
+ if (child->parent == pp->bridge->bus) {
+ root_bus = child;
+ break;
+ }
+ }
+
+ if (!root_bus) {
+ dev_err(pci->dev, "Failed to find downstream devices\n");
+ return -ENODEV;
+ }
+
+ list_for_each_entry(pdev, &root_bus->devices, bus_list) {
+ if (PCI_SLOT(pdev->devfn) == 0) {
+ /* find PCI PM capability in list */
+ ret = pci_find_capability(pdev, PCI_CAP_ID_PM);
+ if (!ret)
+ return ret;
+ /* Check device's PM ability version */
+ pci_read_config_word(pdev, ret + PCI_PM_PMC, &pmc);
+ ver &= pmc;
+ }
+ }
+
+ return ver;
+}
+
static int dw_pcie_pme_turn_off(struct dw_pcie *pci)
{
struct dw_pcie_ob_atu_cfg atu = { 0 };
@@ -924,7 +960,7 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
{
u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
u32 val;
- int ret = 0;
+ int pmc_ver, ret = 0;
/*
* If L1SS is supported, then do not put the link into L2 as some
@@ -933,6 +969,8 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
if (dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL) & PCI_EXP_LNKCTL_ASPM_L1)
return 0;
+ pmc_ver = dwc_get_devices_pmc_version(pci);
+
if (dw_pcie_get_ltssm(pci) > DW_PCIE_LTSSM_DETECT_ACT) {
/* Only send out PME_TURN_OFF when PCIE link is up */
if (pci->pp.ops->pme_turn_off)
@@ -942,7 +980,13 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
if (ret)
return ret;
+ }
+ /*
+ * PMC Ver2.0 device e1000e NIC hangs in LTSSM polling and L2 check.
+ * Only do the L2 check when PMC version is Ver3.0 or later.
+ */
+ if (pmc_ver >= 3) {
ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE,
PCIE_PME_TO_L2_TIMEOUT_US/10,
PCIE_PME_TO_L2_TIMEOUT_US, false, pci);
--
2.37.1
next reply other threads:[~2024-05-14 6:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-14 5:56 Richard Zhu [this message]
2024-05-14 11:03 ` [PATCH v2] PCI: dwc: Fix suspend hang when e1000e network card is connected Fabio Estevam
2024-05-15 1:06 ` Hongxing Zhu
2024-05-14 14:28 ` Frank Li
2024-05-15 1:05 ` Hongxing Zhu
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