Dear coreboot users, The following commit adds Mailbox 3 support for improved panel back- light brigthness control on Intel GMA platforms.
It fixes the problem with 100% brightness on S3 resume.
Please test and review https://review.coreboot.org/#/c/coreboot/+/27711 /
thanks for your work. Are there any documentation or description what Mailbox 3 support is? Where it come from?