[coreboot-gerrit] [M] Change in coreboot[main]: device/pciexp_device.c: Fix setting Max Payload Size

[Michał Żygowski (Code Review)]

Attention is currently required from: Angel Pons, Arthur Heymans, Felix Held, Krystian Hebel, Nico Huber.

Michał Żygowski has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/77338?usp=email )

Change subject: device/pciexp_device.c: Fix setting Max Payload Size
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Patch Set 10:

(1 comment)

File src/device/pciexp_device.c:

https://review.coreboot.org/c/coreboot/+/77338/comment/59ef8961_1a383945 :
PS10, Line 645: 	pciexp_limit_max_payload_ctl(dev->bus->dev, pciexp_configured_max_payload(dev), cap);
> Say you have a chain root -> A -> B -> C, and all devices have the same max except for C, which has more restrictive, smaller value.

As said in other comments, I couldn't test such case, because I have no such HW configuration. That being said, you may be right. pciexp_configure_max_payload might need to be recursive on the way up.

Anyways, it doesn't break the case where the limit is near the root port, moreover it fixes such case. Although the way up might still need some improvements (but also the root -> endp case is not broken with this patch).