[PATCH v6 05/13] PCI: brcmstb: Use bridge reset if available

[Stanimir Varbanov]

Hi Jim,

On 8/16/24 01:57, Jim Quinlan wrote:
> 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 <james.quinlan at broadcom.com>
> ---
>  drivers/pci/controller/pcie-brcmstb.c | 24 +++++++++++++++++++-----
>  1 file changed, 19 insertions(+), 5 deletions(-)

Reviewed-by: Stanimir Varbanov <svarbanov at suse.de>

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.

Any help will be appreciated.

~Stan

[1]
https://github.com/raspberrypi/linux/blob/rpi-6.11.y/drivers/pci/controller/pcie-brcmstb.c#L1711