UIO_010 clarification attempt for https://github.com/riscv-non-isa/ri… #207
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Signed-off-by: Andrei Warkentin <[email protected]>
| descriptions in ACPI and DT. Furthermore, firmware MUST perform BAR resource assignment, | ||
| bridge bus number and window assignments and other reasonable device setting configuration | ||
| (e.g. Max Payload Size) and not assume operating systems to be capable of full PCIe | ||
| resource configuration, or to expect full reconfiguration to be necessary. |
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LGTM. However, when FW allocates the resources it needs to communicate to the OS that they should be preserved (via _DSM in ACPI) . Should we add that requirement as well? REF: PCI FW SPEC 4.6.5.
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Don't have a strong opinion on this one. I'm more concerned about requiring OS behavior. I think FW requesting resources to be preserved is more of a platform choice (tbh, I can only think of scenarios where the OS can't correctly reconfigure due to PCIe support being not compliant).
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Actually I'm pretty confident a blanket policy of requesting OS to preserve configuration is wrong. That may be a necessity in some designs, but cannot be a requirement.
…scv-brs/issues/200