Re: [PATCH v6 06/13] PCI: tegra194: Disable direct speed change for EP
From: Vidya Sagar
Date: Fri Feb 27 2026 - 07:37:28 EST
On 24/02/26 00:11, Manikanta Maddireddy wrote:
> 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")
> Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
> Signed-off-by: Manikanta Maddireddy <mmaddireddy@xxxxxxxxxx>
> ---
> Changes V1 -> V6: 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 8f69c5c5a099..a6868b77e3b7 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -1807,6 +1807,10 @@ 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;
Reviewed-by: Vidya Sagar <vidyas@xxxxxxxxxx>