On 3/22/2017 3:41 PM, Ard Biesheuvel wrote: >> As far as I know, kernel honors resource assignments done by the UEFI BIOS if >> they are correct. Kernel will reassign the resources only if something is wrong. >> > No, the kernel always reassigns all BARs on arm64. I think this is where the problem is. I'm not seeing this happen on QDF2400 which supports ACPI + UEFI BIOS combination only. I see that kernel honored the resources assigned by UEFI BIOS if I compare the BAR addresses. I see reassignment only when something is horribly broken. Then, there would be a bridge configuration invalid message in the boot log to confirm this. > >> Will this code break other platforms/architectures? >> > Which platforms/architectures are you referring to? EFIFB on a PCI > device is currently broken on arm64. In general or on your particular platform? > On x86, it works, given that BARs > are usually not reassigned, and so the patch should be a no-op in that > case (although I'd argue it is still an improvement to check whether > the device that owns the BAR actually has memory decoding enabled > before we attach the framebuffer driver to it) > I'm fine as long as it doesn't break anything. That's why, I'm asking. -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
