Hi Ard,
On 04/28/2017 04:36 PM, Ard Biesheuvel wrote:
Please refer to the patch and the ACPI/arm64 maintainer's reply below if you are interested in understanding why the SolidRun MacchiatoBin board (an arm64 board based on the Marvell Armada 8040 SoC) cannot be fully supported in ACPI mode in the upstream kernel. The change itself is trivial, but it violates a policy regarding standards compliance when it comes to implementing the PCIe root complex.
A lot of us are working behind the scenes on the PCIe problem as far as making sure future designs handle ECAM correctly. I have sympathy for those who started designs a long time ago and didn't have prebuilt OS images to just test and verify they work unmodified. So, I hope something can be done about 8040. BUT that's a /nasty/ quirk. Still, it is just a quirk, and adding one more wouldn't break the universe, it's just that we don't want to make it a sustaining thing that more happen.
However, this is a very useful board when it comes to development involving secure and non-secure firmware, given that all the code it runs is open (ARM Trusted Firmware, U-Boot, UEFI). So perhaps it may be worth considering taking this as a downstream patch in the distros?
Agree. I suspect something can be done about upstream as well. Ultimately, Linux supports hardware that's out there. Pushing back against vendors who are already shipping doesn't necessarily buy us anything, especially for a cheap development platform. What we need to do is establish a trend that the rate of hacks and quirks is not going to increase, but is instead going to net decrease and then cease.
Jon.