Re: port-arm/57643: aarch64: smmu(4) seems mandatory for some SoC and/or memory configuration

[Rin Okuyama <rokuyama.rk%gmail.com@localhost>]

The following reply was made to PR port-arm/57643; it has been noted by GNATS.

From: Rin Okuyama <rokuyama.rk%gmail.com@localhost>
To: Tobias Nygren <tnn%NetBSD.org@localhost>, gnats-bugs%netbsd.org@localhost,
 netbsd-bugs%netbsd.org@localhost
Cc: 
Subject: Re: port-arm/57643: aarch64: smmu(4) seems mandatory for some SoC
 and/or memory configuration
Date: Fri, 6 Oct 2023 22:31:28 +0900

 On 2023/10/05 0:12, Tobias Nygren wrote:
 >> It occurs LK2K with 64 and 32GB memory. On the other hand, I've
 >> never observed similar errors on ROCKPro64 (U-Boot, 4GB memory)
 >> and Quartz64 (UEFI, *8GB* memory).
 > 
 > Just to add a data point. Writing this letter from an LX2K, 64 GB
 > with wm(4) that says it uses 64-bit DMA:
 > 
 > wm0 at pci5 dev 0 function 0, 64-bit DMA: Intel i82574L (rev. 0x00)
 > 
 > This card works fine, as does ahcisata(4) and xhci(4) which also
 > use 64-bit DMA.
 
 Thank you for your feedback.
 
 Hmm, this suggests there may be some bugs in igc(4)...
 
 It turns out that only 2GB of DRAM is mapped below 0xffff ffff
 for LK2K (thanks hikaru@ for pointing it out).
 
 I tried a 2GB SO-DIMM, but UEFI firmware crashes due to sync
 exception (confirmed for multiple revisions). Maybe the vendor
 do not test memory configuration < 4GB; only modules >= 4GB are
 recommended by them:
 
 https://developer.solid-run.com/knowledge-base/lx2160a-cex7-tested-memory-so-dimms/
 
 I will get another module and test for sure...
 
 So, the current status of igc(4) is not perfect, but I will
 send a pull up request for netbsd-10; it would be better to
 receive many feedback from NetBSD 10.0 RC1 testers.
 
 Thanks,
 rin