Re: [PATCH v7 0/3] PCI: rockchip: 5.0 GT/s speed discouraged by Rockchip

[Shawn Lin <shawn.lin@rock-chips.com>]

Hi Geraldo

在 2026/06/16 星期二 23:24, 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, including data loss.
> 
> Drop all code related to 5.0 GT/s operational speed from this driver.
> 

Apologies for the very late notice that this series is still pending.
FWIW,
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>

> Endpoint Mode driver was not tested.
> 
> Changes in v7:
> - In pcie-rockchip.c (PATCH 3) drop unreachable code
> - Link to v6: https://lore.kernel.org/all/cover.1781207474.git.geraldogabriel@gmail.com/T/
> 
> Changes in v6:
> - Squashed patches 3 & 4 together as suggested by Mani
> - More formal warning message as suggested by Dragan
> - Set the 2.5 GT/s bit regardless of if link-speed is set to 2
> - Link to v5: https://lore.kernel.org/all/cover.1772239598.git.geraldogabriel@gmail.com/T/
> 
> Changes in v5:
> - Changed commit order to not break builds and adjusted copy pasted
>    commit message. (thanks Charalampos!)
> - Reintroduced behavior to force 2.5 GT/s in case there's something
>    non-default in the DT. (thanks Dragan!)
> - Link to v4: https://lore.kernel.org/linux-rockchip/cover.1772169998.git.geraldogabriel@gmail.com/T/
> 
> Changes in v4:
> - Incorporate suggestion by Bjorn and refined by Dragan to drop the
>    "catastrophic" code
> - Link to v3: https://lore.kernel.org/linux-rockchip/cover.1772057799.git.geraldogabriel@gmail.com/T/
> 
> Changes in v3:
> - Clarify warning message even though Rockchip won't disclose details
> - Drop DT changes as they were applied as subset by Heiko
> - Link to v2: https://lore.kernel.org/all/cover.1763415705.git.geraldogabriel@gmail.com/T/
> 
> 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/T/
> 
> Geraldo Nascimento (3):
>    PCI: rockchip-ep: do not attempt 5.0 GT/s retraining
>    PCI: rockchip-host: do not attempt 5.0 GT/s retraining
>    PCI: rockchip: drive at 2.5 GT/s, error other speeds
> 
>   drivers/pci/controller/pcie-rockchip-ep.c   | 13 -------------
>   drivers/pci/controller/pcie-rockchip-host.c | 20 --------------------
>   drivers/pci/controller/pcie-rockchip.c      | 14 ++++++--------
>   drivers/pci/controller/pcie-rockchip.h      |  3 ---
>   4 files changed, 6 insertions(+), 44 deletions(-)
>