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

[Nico Huber (Code Review)]

Attention is currently required from: Angel Pons, Arthur Heymans, Felix Held, Kyösti Mälkki, Michał Żygowski.

Nico Huber 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 4: Code-Review+1

(3 comments)

Patchset:

PS2:
> Implemented your suggested approach, Nico. […]

Thanks, looks good! Only two minor suggestions...

Let's let others have a look.

File src/device/pciexp_device.c:

https://review.coreboot.org/c/coreboot/+/77338/comment/e3fc1a71_9ba9ebdc :
PS4, Line 603: 	pci_write_config16(dev, pcie_cap + PCI_EXP_DEVCTL, devctl);
We have pci_update_config*() functions now, so this could also be

pci_update_config16(dev, pcie_cap + PCI_EXP_DEVCTL, ~PCI_EVP_DEVCTL_PAYLOAD, max_payload << 5);

https://review.coreboot.org/c/coreboot/+/77338/comment/3a6c3c68_e5782ab0 :
PS4, Line 654: {
As a small optimization we could look up the caps here and pass the
offsets down. pciexp_tune_dev() already knows them and could pass them
to pciexp_configure_max_payload() respectively.