| Message ID | 1715663358-8900-1-git-send-email-hongxing.zhu@nxp.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v1] PCI: dwc: Fix resume failure if no EP is connected at some platforms. | expand |
On Tue, May 14, 2024 at 01:09:18PM +0800, Richard Zhu wrote: > The dw_pcie_suspend_noirq() function currently returns success directly > if no endpoint (EP) device is connected. However, on some platforms, power > loss occurs during suspend, causing dw_resume() to do nothing in this case. > This results in a system halt because the DWC controller is not initialized > after power-on during resume. > > Change call to deinit() in suspend and init() at resume regardless of > whether there are EP device connections or not. It is not harmful to > perform deinit() and init() again for the no power-off case, and it keeps > the code simple and consistent in logic. > > Fixes: 4774faf854f5 ("PCI: dwc: Implement generic suspend/resume functionality") > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> > --- > https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/log/?h=controller/dwc > This patch depends on the branch listed above, because it's not in pci-next. > But suppose it will be in there soon. > > .../pci/controller/dwc/pcie-designware-host.c | 30 +++++++++---------- > 1 file changed, 15 insertions(+), 15 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c > index a0822d5371bc5..cb8c3c2bcc790 100644 > --- a/drivers/pci/controller/dwc/pcie-designware-host.c > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c > @@ -933,23 +933,23 @@ 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) > - pci->pp.ops->pme_turn_off(&pci->pp); > - else > - ret = dw_pcie_pme_turn_off(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) > + pci->pp.ops->pme_turn_off(&pci->pp); > + 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, > - PCIE_PME_TO_L2_TIMEOUT_US/10, > - PCIE_PME_TO_L2_TIMEOUT_US, false, pci); > - if (ret) { > - dev_err(pci->dev, "Timeout waiting for L2 entry! LTSSM: 0x%x\n", val); > - return ret; > + 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); > + if (ret) { > + dev_err(pci->dev, "Timeout waiting for L2 entry! LTSSM: 0x%x\n", val); > + return ret; > + } > } > > if (pci->pp.ops->deinit) > -- > 2.37.1 >
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index a0822d5371bc5..cb8c3c2bcc790 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -933,23 +933,23 @@ 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) - pci->pp.ops->pme_turn_off(&pci->pp); - else - ret = dw_pcie_pme_turn_off(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) + pci->pp.ops->pme_turn_off(&pci->pp); + 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, - PCIE_PME_TO_L2_TIMEOUT_US/10, - PCIE_PME_TO_L2_TIMEOUT_US, false, pci); - if (ret) { - dev_err(pci->dev, "Timeout waiting for L2 entry! LTSSM: 0x%x\n", val); - return ret; + 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); + if (ret) { + dev_err(pci->dev, "Timeout waiting for L2 entry! LTSSM: 0x%x\n", val); + return ret; + } } if (pci->pp.ops->deinit)
The dw_pcie_suspend_noirq() function currently returns success directly if no endpoint (EP) device is connected. However, on some platforms, power loss occurs during suspend, causing dw_resume() to do nothing in this case. This results in a system halt because the DWC controller is not initialized after power-on during resume. Change call to deinit() in suspend and init() at resume regardless of whether there are EP device connections or not. It is not harmful to perform deinit() and init() again for the no power-off case, and it keeps the code simple and consistent in logic. Fixes: 4774faf854f5 ("PCI: dwc: Implement generic suspend/resume functionality") Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com> --- https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/log/?h=controller/dwc This patch depends on the branch listed above, because it's not in pci-next. But suppose it will be in there soon. .../pci/controller/dwc/pcie-designware-host.c | 30 +++++++++---------- 1 file changed, 15 insertions(+), 15 deletions(-)