[PATCH 6.6.y 2/2] PCI: rockchip: Set Target Link Speed to 5.0 GT/s before retraining

[Sasha Levin <sashal@kernel.org>]

From: Geraldo Nascimento <geraldogabriel@gmail.com>

[ Upstream commit 114b06ee108cabc82b995fbac6672230a9776936 ]

Rockchip controllers can support up to 5.0 GT/s link speed. But the driver
doesn't set the Target Link Speed currently. This may cause failure in
retraining the link to 5.0 GT/s if supported by the endpoint. So set the
Target Link Speed to 5.0 GT/s in the Link Control and Status Register 2.

Fixes: e77f847df54c ("PCI: rockchip: Add Rockchip PCIe controller support")
Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
[mani: fixed whitespace warning, commit message rewording, added fixes tag]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/0afa6bc47b7f50e2e81b0b47d51c66feb0fb565f.1751322015.git.geraldogabriel@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 b262480a12b0..c25f32abbdf6 100644
--- a/drivers/pci/controller/pcie-rockchip-host.c
+++ b/drivers/pci/controller/pcie-rockchip-host.c
@@ -339,6 +339,10 @@ 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);
-- 
2.50.1