Re: [PATCH v2 0/4] PCI: rockchip: 5.0 GT/s speed may be dangerous

Shawn Lin
2025-11-18T00:44:06Z

在 2025/11/18 星期二 5:46, Geraldo Nascimento 写道:
> Dragan Simic already had warned me of potential issues with 5.0 GT/s
> speed operation in Rockchip PCIe. However, in recent interactions
> with Shawn Lin from Rockchip it came to my attention there's grave
> danger in the unknown errata regarding 5.0 GT/s operational speed
> of their PCIe core. Even if the odds are low, to contain any damage,
> let's cover the remaining corner-cases where the default would lead
> to 5.0 GT/s operation as well as add a comment to Root Complex driver
> core, documenting this danger. Furthermore, remove redundant
> declaration of max-link-speed from rk3399-nanopi-r4s.dtsi
>
> Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
>

Thanks for fixing these.

Acked-by: Shawn Lin <shawn.lin@rock-chips.com>

> ---
>
> Changes in v2:
> - hard limit to 2.5 GT/s, not just warn
> - add Reported-by: and Reviewed-by: Dragan Simic
> - remove redundant declaration of max-link-speed from helios64 dts
> - fix Link: of helios64 patch
> - simplify RC mode comment
> - Link to v1: https://lore.kernel.org/all/aRhR79u5BPtRRFw3@geday/
>
> Geraldo Nascimento (4):
> PCI: rockchip: limit RK3399 to 2.5 GT/s to prevent damage
> PCI: rockchip-host: comment danger of 5.0 GT/s speed
> arm64: dts: rockchip: remove dangerous max-link-speed from helios64
> arm64: dts: rockchip: remove redundant max-link-speed from nanopi-r4s
>
> arch/arm64/boot/dts/rockchip/rk3399-kobol-helios64.dts | 1 -
> arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dtsi | 1 -
> drivers/pci/controller/pcie-rockchip-host.c | 3 +++
> drivers/pci/controller/pcie-rockchip.c | 10 ++++++++--
> 4 files changed, 11 insertions(+), 4 deletions(-)