[PATCH v2 1/4] PCI: rockchip: limit RK3399 to 2.5 GT/s to prevent damage
From: Geraldo Nascimento <hidden>
Date: 2025-11-17 21:47:15
Also in:
linux-devicetree, linux-pci, linux-rockchip, lkml
Subsystem:
arm/rockchip soc support, pci native host bridge and endpoint drivers, pci subsystem, pcie driver for rockchip, the rest · Maintainers:
Heiko Stuebner, Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Shawn Lin, Linus Torvalds
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/ (local) Cc: stable@vger.kernel.org Reported-by: Dragan Simic <redacted> Reported-by: Shawn Lin <shawn.lin@rock-chips.com> Reviewed-by: Dragan Simic <redacted> Signed-off-by: Geraldo Nascimento <redacted> --- 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];
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2.49.0