Hi Florian,

On 8/19/24 22:07, Florian Fainelli wrote:

On 8/17/24 10:41, Stanimir Varbanov wrote:

quoted

Hi Jim,

On 8/16/24 01:57, Jim Quinlan wrote:

quoted

The 7712 SOC has a bridge reset which can be described in the device
tree.
Use it if present.  Otherwise, continue to use the legacy method to
reset
the bridge.

Signed-off-by: Jim Quinlan <redacted>
---
  drivers/pci/controller/pcie-brcmstb.c | 24 +++++++++++++++++++-----
  1 file changed, 19 insertions(+), 5 deletions(-)

Reviewed-by: Stanimir Varbanov <redacted>

One problem though on RPi5 (bcm2712).

With this series applied + my WIP patches for enablement of PCIe on
bcm2712 when enable the pcie1 and pcie2 root ports in dts, I see kernel
boot stuck on pcie2 enumeration and I have to add this [1] to make it
work again.

Some more info about resets used:

pcie0 @ 100000:
    resets = <&bcm_reset 5>, <&bcm_reset 42>, <&pcie_rescal>;
    reset-names = "swinit", "bridge", "rescal";

pcie1 @ 110000:
    resets = <&bcm_reset 7>, <&bcm_reset 43>, <&pcie_rescal>;
    reset-names = "swinit", "bridge", "rescal";

pcie2 @ 120000:
    resets = <&bcm_reset 9>, <&bcm_reset 44>, <&pcie_rescal>;
    reset-names = "swinit", "bridge", "rescal"; >

I changed "swinit" reset for pcie2 to <&bcm_reset 9> (it is 32 in
downstream rpi kernel) because otherwise I'm unable to enumerate RP1
south bridge at all.

The value 9 is unused, so I suppose it does not really hurt to use it,
but it is also unlikely to achieve what you desire. 32 is the correct
value since pcie2_sw_init is bit 0 within SW_INIT_1 (second bank of
resets).

Good to know that 9 is not the proper reset line, thank you.

Unfortunately, I'm unable to make it work with the proper reset line (32).

The file link you provided appears to be lacking support for the
"swinit" reset line, is that intentional? I don't think you can assume

No idea why downstream RPi kernel does not use swinit reset.

this will work without.

If I do not populate swinit in PCIe DT node it works i.e. PCI
enumeration is working and RP1 south-bridge is functional.

~Stan