[PATCH v7 06/13] PCI: tegra194: Disable direct speed change for EP

From: Manikanta Maddireddy

Date: Tue Mar 03 2026 - 01:57:04 EST


From: Vidya Sagar <vidyas@xxxxxxxxxx>

Disable direct speed change for the Endpoint to prevent it from initiating
the speed change post physical layer link up at gen1. This leaves the speed
change ownership with the host.

Fixes: c57247f940e8 ("PCI: tegra: Add support for PCIe endpoint mode in Tegra194")
Reviewed-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Tested-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
Signed-off-by: Manikanta Maddireddy <mmaddireddy@xxxxxxxxxx>
---
Changes V1 -> V7: None

drivers/pci/controller/dwc/pcie-tegra194.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 7dcf3e3596dd..2da3478f0b5f 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1805,6 +1805,10 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)

reset_control_deassert(pcie->core_rst);

+ val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
+ val &= ~PORT_LOGIC_SPEED_CHANGE;
+ dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, val);
+
if (pcie->update_fc_fixup) {
val = dw_pcie_readl_dbi(pci, CFG_TIMER_CTRL_MAX_FUNC_NUM_OFF);
val |= 0x1 << CFG_TIMER_CTRL_ACK_NAK_SHIFT;
--
2.34.1