[PATCH v2] PCI: imx6: Enable L1SS support when supports_clkreq is true

[hongxing . zhu]

From: Richard Zhu <hongxing.zhu@xxxxxxx>

Enable L1SS for the i.MX6 PCIe controller when the `supports_clkreq` flag
is set. This ensures that the PCIe endpoint can enter low-power states
efficiently when the link is not in use.

The commit a00bba406b5a ("PCI: dwc: Advertise L1 PM Substates only if
driver requests it") clears L1SS capabilities by default. However, the
i.MX PCIe controller supports L1SS as indicated by the settings in the L1SS
capabilities register. By setting `dw_pcie.l1ss_support` to true when
`supports_clkreq` is true, enable proper utilization of L1SS for i.MX6 PCIe
configurations.

Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
---
Changes in v2:
Updated the commit message to provide an explanation of why enabling L1SS
support is necessary for the i.MX6 PCIe controller when the supports_clkreq
flag is set.
---
 drivers/pci/controller/dwc/pci-imx6.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 83fbd998551d0..4eee02e135656 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1501,6 +1501,9 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp)
 
 	imx_setup_phy_mpll(imx_pcie);
 
+	if (imx_pcie->supports_clkreq)
+		pci->l1ss_support = true;
+
 	return 0;
 
 err_phy_off:
-- 
2.34.1