Commit 112aba9a authored by Richard Zhu's avatar Richard Zhu Committed by Bjorn Helgaas
Browse files

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: default avatarRichard Zhu <hongxing.zhu@nxp.com>
[kwilczynski: commit log]
Signed-off-by: default avatarKrzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: commit log]
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarFrank Li <Frank.Li@nxp.com>
Reviewed-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
parent 86a016e2

drivers/pci/controller/dwc/pcie-designware-host.c

+17 −10
Original line number Diff line number Diff line
@@ -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;

	}



	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);

drivers/pci/controller/dwc/pcie-designware.h

+1 −0
Original line number Diff line number Diff line
@@ -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,