onboard wireless on rpi4

[Mark Millard]

On 2020-Sep-6, at 11:20, Mark Millard <marklmi at yahoo.com> wrote:

> On 2020-Sep-6, at 08:20, Robert Crowston via freebsd-arm <freebsd-arm at freebsd.org> wrote:
> 
>> That's interesting: OpenBSD is allowing only the lowest 1 GB of memory for DMA; the documentation I obtained suggests the first 3 GB should be accessible. I am experimenting with this new lower bound.
> 
> https://rpi4-uefi.dev/tag/netbsd/ reports:
> 
> QUOTE
> NetBSD also is the only OS today to fully support ACPI _DMA descriptors for describing DMA translations/constraints. This is very important for supporting Pi and Pi-like platforms via straight-up ACPI and without platform DMA quirks. 
> END QUOTE

I'll also note that for the last month or so the linux 5.8 kernel
has use of: acpi_dma_get_range(dev, &dmaaddr, &offset, &size) 
and rc_dma_get_range(dev, &size) and nc_dma_get_range(dev, &size)
in iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
in root/drivers/acpi/arm64/iort.c .

(There apparently still is/was also some sort of zero copy DMA
problem on the XHCI controller for 5.8. Still,
https://github.com/pftf/RPi4/issues/20 was closed based on the
linux progress in 5.8 : booting linux with more than 3072 MiB
was working.)


>> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
>> On Sunday, 6 September 2020 13:40, Klaus Cucinauomo <maciphone2 at googlemail.com> wrote:
>> 
>>>> Am 06.09.2020 um 06:40 schrieb Warner Losh <imp at bsdimp.com>:
>>>> 
>>>> I thought I read they added the busdma constraints we are missing…
>>>> 
>>>> Warner
>>> 
>>> Yes, for OpenBSD I thought the same , to be a little more specific :
>>> 
>>> https://github.com/openbsd/src/commit/aae395593ca184a639a1c158ceb4b2132d85e7c2
>>> 
>>> https://github.com/openbsd/src/commit/a88d14946aed5dc48e4e700486795c8d171576d0
>> 
> 
> 



===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)