On 18.04.2024 15:13, Dag B wrote:
On 18.04.2024 14:24, Christian König wrote:
Am 18.04.24 um 12:42 schrieb Dag B:
[SNIP]
Is there a good ELI13 resource explaining how resizable BAR works
in Linux?
My current kernel command-line contains: pci=assign-busses,realloc
That's a really really bad idea. The "assign-busses" flag was
introduced to get 20year old laptops to see their cardbus PCI devices.
I threw a lot of mud at the wall to see what stuck. Removing it now
did not make a big difference.
Removing realloc prevents the second TB3 GPU from being initialized,
so keeping that for now.
That's really interesting. Why does it fail without that?
It basically means that your BIOS is somehow broken and only the
Linux PCI subsystem is able to assign resources correctly.
Please provide the output of "sudo lspci -v" and "sudo lspci -tv" as
file attachment (*not* inline in a mail!).
In case I have expressed myself awkwardly, the realloc=off case
appears to make the device driver have issues with the second GPU.
I have attached both outputs, for realloc=off.
Not knowing what is considered acceptable message sizes on this m/l, I
uploaded the same for realloc=on, as well as output from dmesg for
both cases to:
https://github.com/dagbdagb/p53
If the m/l has mechanisms to archive attachments and replace them with
links, I'll redo the exercise in a follow-up email. I understand the
value of having the 'context' of the discussion readily available in
one place.
Dag B
I now have one GPU enabled with the full-fat BAR. The other has issues
assigning address space for the BARs with this config, and cannot be
initialized.
pci=realloc=on,hpiosize=64K,hpmemsize=64M,hpmmioprefsize=64G,pcie_scan_all,hpbussize=0x33
..results in:
Capabilities: [bb0 v1] Physical Resizable BAR
BAR 0: current size: 16MB, supported: 16MB
BAR 1: current size: 32GB, supported: 64MB 128MB 256MB 512MB
1GB 2GB 4GB 8GB 16GB 32GB
BAR 3: current size: 32MB, supported: 32MB
Still mostly throwing mud at the wall, but the hp* options do appear to
make a difference. Would love to understand these options better.,
Dag B
