Hi Jeremy, Am 05.08.21 um 23:11 schrieb Jeremy Linton: > The PFTF CM4 is an ACPI platform that is following the PCIe SMCCC > standard because its PCIe config space isn't ECAM compliant and is > split into two parts. One part for the root port registers and a > moveable window which points at a given device's 4K config space. > Thus it doesn't have a MCFG (and really any MCFG provided would be > nonsense anyway). As linux doesn't support the PCIe SMCCC standard > we key off a linux specific host bridge _DSD to add custom ECAM > ops and cfgres. The cfg op selects between those two regions, as > well as disallowing problematic accesses, particularly if the link > is down because there isn't an attached device. i just want to inform you, that i recently submitted the inital patch series for DT support regarding CM4 [1]. I left out anything related to PCIe (including downstream changes to pcie-brcmstb). Best regards Stefan [1] - https://marc.info/?l=linux-arm-kernel&m=162782110325813&w=2
