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| author | Richard Zhu <hongxing.zhu@nxp.com> | 2024-12-10 16:15:57 +0800 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2025-01-18 13:38:34 -0600 |
| commit | 112aba9a79345aae81c508d92c1e9711c81d791c (patch) | |
| tree | 791e6cd5c66d9c5583875d32133a90a9719192b3 /drivers/pci/controller/dwc | |
| parent | 86a016e278b78cc2281edd4ffaddbc011c87a593 (diff) | |
| download | linux-112aba9a79345aae81c508d92c1e9711c81d791c.tar.gz linux-112aba9a79345aae81c508d92c1e9711c81d791c.tar.bz2 linux-112aba9a79345aae81c508d92c1e9711c81d791c.zip | |
PCI: dwc: Remove LTSSM state test in dw_pcie_suspend_noirq()
It's safe to send PME_TURN_OFF message regardless of whether the link is up
or down, so don't test the LTSSM state before sending the PME_TURN_OFF
message.
Only print an error message when the LTSSM is not in DETECT or POLL. There
shouldn't be an error when no Endpoint is connected at all.
Link: https://lore.kernel.org/r/20241210081557.163555-3-hongxing.zhu@nxp.com
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Diffstat (limited to 'drivers/pci/controller/dwc')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware-host.c | 27 | ||||
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware.h | 1 |
2 files changed, 18 insertions, 10 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index d6d5fff1121c..f43753bb7888 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -924,7 +924,7 @@ 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 ret; /* * If L1SS is supported, then do not put the link into L2 as some @@ -933,25 +933,32 @@ 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; - if (dw_pcie_get_ltssm(pci) <= DW_PCIE_LTSSM_DETECT_ACT) - return 0; - - if (pci->pp.ops->pme_turn_off) + if (pci->pp.ops->pme_turn_off) { pci->pp.ops->pme_turn_off(&pci->pp); - else + } else { ret = dw_pcie_pme_turn_off(pci); + if (ret) + return ret; + } - if (ret) - return ret; - - ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE, + ret = read_poll_timeout(dw_pcie_get_ltssm, val, + val == DW_PCIE_LTSSM_L2_IDLE || + val <= DW_PCIE_LTSSM_DETECT_WAIT, PCIE_PME_TO_L2_TIMEOUT_US/10, PCIE_PME_TO_L2_TIMEOUT_US, false, pci); if (ret) { + /* Only log message when LTSSM isn't in DETECT or POLL */ dev_err(pci->dev, "Timeout waiting for L2 entry! LTSSM: 0x%x\n", val); return ret; } + /* + * Per PCIe r6.0, sec 5.3.3.2.1, software should wait at least + * 100ns after L2/L3 Ready before turning off refclock and + * main power. This is harmless when no endpoint is connected. + */ + udelay(1); + dw_pcie_stop_link(pci); if (pci->pp.ops->deinit) pci->pp.ops->deinit(&pci->pp); diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 1d0ec47e1986..8c0222f019d7 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -330,6 +330,7 @@ enum dw_pcie_ltssm { /* Need to align with PCIE_PORT_DEBUG0 bits 0:5 */ DW_PCIE_LTSSM_DETECT_QUIET = 0x0, DW_PCIE_LTSSM_DETECT_ACT = 0x1, + DW_PCIE_LTSSM_DETECT_WAIT = 0x6, DW_PCIE_LTSSM_L0 = 0x11, DW_PCIE_LTSSM_L2_IDLE = 0x15, |