From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Currently, dw_pcie::max_link_speed has a valid value only if the controller
driver restricts the maximum link speed in the driver or if the platform
does so in the devicetree using the 'max-link-speed' property.
But having the maximum supported link speed of the platform would be
helpful for the vendor drivers to configure any link specific settings.
So in the case of non-valid value in dw_pcie::max_link_speed, just cache
the hardware default value from Link Capability register.
While at it, let's also remove the 'max_link_speed' argument to the
dw_pcie_link_set_max_speed() function since the value can be retrieved
within the function.
Reviewed-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
Tested-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-designware.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 86c49ba097c6..7c4e316eb749 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -687,16 +687,27 @@ void dw_pcie_upconfig_setup(struct dw_pcie *pci)
}
EXPORT_SYMBOL_GPL(dw_pcie_upconfig_setup);
-static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 max_link_speed)
+static void dw_pcie_link_set_max_speed(struct dw_pcie *pci)
{
u32 cap, ctrl2, link_speed;
u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
cap = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
+
+ /*
+ * Even if the platform doesn't want to limit the maximum link speed,
+ * just cache the hardware default value so that the vendor drivers can
+ * use it to do any link specific configuration.
+ */
+ if (pci->max_link_speed < 1) {
+ pci->max_link_speed = FIELD_GET(PCI_EXP_LNKCAP_SLS, cap);
+ return;
+ }
+
ctrl2 = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCTL2);
ctrl2 &= ~PCI_EXP_LNKCTL2_TLS;
- switch (pcie_link_speed[max_link_speed]) {
+ switch (pcie_link_speed[pci->max_link_speed]) {
case PCIE_SPEED_2_5GT:
link_speed = PCI_EXP_LNKCTL2_TLS_2_5GT;
break;
@@ -1058,8 +1069,7 @@ void dw_pcie_setup(struct dw_pcie *pci)
{
u32 val;
- if (pci->max_link_speed > 0)
- dw_pcie_link_set_max_speed(pci, pci->max_link_speed);
+ dw_pcie_link_set_max_speed(pci);
/* Configure Gen1 N_FTS */
if (pci->n_fts[0]) {
--
2.25.1
