[PATCH v2 1/4] PCI: rockchip: limit RK3399 to 2.5 GT/s to prevent damage

Geraldo Nascimento
2025-11-17T21:47:24Z

Shawn Lin from Rockchip has reiterated that there may be danger in using
their PCIe with 5.0 GT/s speeds. Warn the user if they make a DT change
from the default and drive at 2.5 GT/s only, even if the DT
max-link-speed property is invalid or inexistent.

This change is corroborated by RK3399 official datasheet [1], which
says maximum link speed for this platform is 2.5 GT/s.

[1] https://opensource.rock-chips.com/images/d/d7/Rockchip_RK3399_Datasheet_V2.1-20200323.pdf

Fixes: 956cd99b35a8 ("PCI: rockchip: Separate common code from RC driver")
Link: https://lore.kernel.org/all/ffd05070-9879-4468-94e3-b88968b4c21b@rock-chips.com/
Cc: stable@vger.kernel.org
Reported-by: Dragan Simic <dsimic@manjaro.org>
Reported-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Dragan Simic <dsimic@manjaro.org>
Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
---
drivers/pci/controller/pcie-rockchip.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pcie-rockchip.c b/drivers/pci/controller/pcie-rockchip.c
index 0f88da378805..992ccf4b139e 100644
--- a/drivers/pci/controller/pcie-rockchip.c
+++ b/drivers/pci/controller/pcie-rockchip.c
@@ -66,8 +66,14 @@ int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)
}

rockchip->link_gen = of_pci_get_max_link_speed(node);
- if (rockchip->link_gen < 0 || rockchip->link_gen > 2)
- rockchip->link_gen = 2;
+ if (rockchip->link_gen < 0 || rockchip->link_gen > 2) {
+ rockchip->link_gen = 1;
+ dev_warn(dev, "invalid max-link-speed, set to 2.5 GT/s\n");
+ }
+ else if (rockchip->link_gen == 2) {
+ rockchip->link_gen = 1;
+ dev_warn(dev, "5.0 GT/s is dangerous, set to 2.5 GT/s\n");
+ }

for (i = 0; i < ROCKCHIP_NUM_PM_RSTS; i++)
rockchip->pm_rsts[i].id = rockchip_pci_pm_rsts[i];
--
2.49.0