Re: [PATCH] PCI: dw-rockchip: Skip waiting for link up

FUKAUMI Naoki
2025-11-09T23:18:08Z

Hi Niklas,

On 11/9/25 21:28, Niklas Cassel wrote:
> On Sun, Nov 09, 2025 at 01:42:23PM +0900, FUKAUMI Naoki wrote:
>> Hi Niklas,
>>
>> On 11/8/25 22:27, Niklas Cassel wrote:
>> (snip)> (And btw. please test with the latest 6.18-rc, as, from experience,
>> the
>>> ASPM problems in earlier RCs can result in some weird problems that are
>>> not immediately deduced to be caused by the ASPM enablement.)
>>
>> Here is dmesg from v6.18-rc4:
>> https://gist.github.com/RadxaNaoki/40e1d049bff4f1d2d4773a5ba0ed9dff
>
> Same problem as before:
> [ 1.732538] pci_bus 0004:43: busn_res: can not insert [bus 43-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
> [ 1.732645] pci_bus 0004:43: busn_res: [bus 43-41] end is updated to 43
> [ 1.732651] pci_bus 0004:43: busn_res: can not insert [bus 43] under [bus 42-41] (conflicts with (null) [bus 42-41])
> [ 1.732661] pci 0004:42:00.0: devices behind bridge are unusable because [bus 43] cannot be assigned for them
> [ 1.732840] pci_bus 0004:44: busn_res: can not insert [bus 44-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
> [ 1.732947] pci_bus 0004:44: busn_res: [bus 44-41] end is updated to 44
> [ 1.732952] pci_bus 0004:44: busn_res: can not insert [bus 44] under [bus 42-41] (conflicts with (null) [bus 42-41])
> [ 1.732962] pci 0004:42:02.0: devices behind bridge are unusable because [bus 44] cannot be assigned for them
> [ 1.733134] pci_bus 0004:45: busn_res: can not insert [bus 45-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
> [ 1.733246] pci_bus 0004:45: busn_res: [bus 45-41] end is updated to 45
> [ 1.733255] pci_bus 0004:45: busn_res: can not insert [bus 45] under [bus 42-41] (conflicts with (null) [bus 42-41])
> [ 1.733266] pci 0004:42:06.0: devices behind bridge are unusable because [bus 45] cannot be assigned for them
> [ 1.733438] pci_bus 0004:46: busn_res: can not insert [bus 46-41] under [bus 42-41] (conflicts with (null) [bus 42-41])
> [ 1.733544] pci_bus 0004:46: busn_res: [bus 46-41] end is updated to 46
> [ 1.733550] pci_bus 0004:46: busn_res: can not insert [bus 46] under [bus 42-41] (conflicts with (null) [bus 42-41])
> [ 1.733560] pci 0004:42:0e.0: devices behind bridge are unusable because [bus 46] cannot be assigned for them
> [ 1.733571] pci_bus 0004:42: busn_res: [bus 42-41] end is updated to 46
> [ 1.733575] pci_bus 0004:42: busn_res: can not insert [bus 42-46] under [bus 41] (conflicts with (null) [bus 41])
> [ 1.733585] pci 0004:41:00.0: devices behind bridge are unusable because [bus 42-46] cannot be assigned for them
> [ 1.733596] pcieport 0004:40:00.0: bridge has subordinate 41 but max busn 46
>
>
> Seems like the ASM2806 switch, for some reason, is not ready.
>
> One change that Diederik pointed out is that in the "good" case,
> the link is always in Gen1 speed.
>
> Perhaps you could build with CONFIG_PCI_QUIRKS=y and try this patch:
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 214ed060ca1b..ac134d95a97f 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -96,6 +96,7 @@ int pcie_failed_link_retrain(struct pci_dev *dev)
> {
> static const struct pci_device_id ids[] = {
> { PCI_VDEVICE(ASMEDIA, 0x2824) }, /* ASMedia ASM2824 */
> + { PCI_VDEVICE(ASMEDIA, 0x2806) }, /* ASMedia ASM2806 */
> {}
> };
> u16 lnksta, lnkctl2;

It doesn't help with either probing behind the bridge or the link speed.

> If that does not work, perhaps you could try this patch
> (assuming that all Rock 5C:s have a ASM2806 on pcie2x1l2):

ROCK 5C has a PCIe FPC connector and I'm using Dual 2.5G Router HAT.
https://radxa.com/products/rock5/5c#techspec
https://radxa.com/products/accessories/dual-2-5g-router-hat

Regarding the link speed, I initially suspected the FPC connector and/or
cable might be the issue. However, I tried the Dual 2.5G Router HAT with
the ROCK 5A (which uses a different cable), and I got the same result.

BTW, the link speed varies between 2Gb/s and 4Gb/s depending on the
reboot. (with or without quirk)

Best regards,

--
FUKAUMI Naoki
Radxa Computer (Shenzhen) Co., Ltd.

> diff --git a/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts b/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts
> index dd7317bab613..26f8539d934a 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts
> @@ -452,6 +452,7 @@ &pcie2x1l2 {
> pinctrl-0 = <&pcie20x1_2_perstn_m0>;
> reset-gpios = <&gpio3 RK_PD1 GPIO_ACTIVE_HIGH>;
> vpcie3v3-supply = <&pcie2x1l2_3v3>;
> + max-link-speed = <1>;
> status = "okay";
> };
>
>
>
> Kind regards,
> Niklas
>