Current code may fail Gen2 retraining if Target Link Speed
is set to 2.5 GT/s in Link Control and Status Register 2.
Set it to 5.0 GT/s accordingly.

Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
---
 drivers/pci/controller/pcie-rockchip-host.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c
index 65653218b9ab..7a0b6ebb7c27 100644
--- a/drivers/pci/controller/pcie-rockchip-host.c
+++ b/drivers/pci/controller/pcie-rockchip-host.c
@@ -341,6 +341,10 @@ static int rockchip_pcie_host_init_port(struct rockchip_pcie *rockchip)
 		 * Enable retrain for gen2. This should be configured only after
 		 * gen1 finished.
 		 */
+		status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_CR + PCI_EXP_LNKCTL2);
+		status &= ~PCI_EXP_LNKCTL2_TLS;
+		status |= PCI_EXP_LNKCTL2_TLS_5_0GT;
+		rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_CR + PCI_EXP_LNKCTL2);
 		status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_CR + PCI_EXP_LNKCTL);
 		status |= PCI_EXP_LNKCTL_RL;
 		rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_CR + PCI_EXP_LNKCTL);
-- 
2.49.0

On Fri, Jun 13, 2025 at 12:06:00PM -0300, Geraldo Nascimento wrote:
> Current code may fail Gen2 retraining if Target Link Speed
> is set to 2.5 GT/s in Link Control and Status Register 2.
> Set it to 5.0 GT/s accordingly.

Nit: I don't know what "Gen2" means (and the spec warns against
assuming spec rev maps one-to-one to a speed), so try to use the
actual speed instead of "GenX".

Bjorn

On Fri, Jun 13, 2025 at 03:15:43PM -0500, Bjorn Helgaas wrote:
> On Fri, Jun 13, 2025 at 12:06:00PM -0300, Geraldo Nascimento wrote:
> > Current code may fail Gen2 retraining if Target Link Speed
> > is set to 2.5 GT/s in Link Control and Status Register 2.
> > Set it to 5.0 GT/s accordingly.
> 
> Nit: I don't know what "Gen2" means (and the spec warns against
> assuming spec rev maps one-to-one to a speed), so try to use the
> actual speed instead of "GenX".

Ah, excellent catch. I'll make sure to adjust the commit message!

Geraldo Nascimento

> 
> Bjorn