Re: [PATCH] ata: ahci: force 32-bit DMA for ASMedia ASM1166

[Damien Le Moal <dlemoal@kernel.org>]

On 6/21/26 19:08, Alvin Lim wrote:
> The ASMedia ASM1166 SATA controller (1b21:1166) advertises 64-bit DMA
> support (AHCI CAP.S64A), but on systems with the IOMMU enabled - where it
> can be handed DMA addresses above 4 GB - it silently corrupts data in
> transit. Reads return different, wrong data on each access. SMART is clean,
> there are no SATA link resets and no MCE is raised, so the corruption is
> invisible until it surfaces as filesystem metadata errors (XFS EUCLEAN)
> or, on Ceph, mass scrub errors across multiple independent filesystems at
> once - i.e. host-level, not filesystem-level.
> 
> This is the same failure mode already quirked for other controllers that
> falsely claim working 64-bit DMA. See commit 105c42566a55 ("ata: ahci:
> force 32-bit DMA for JMicron JMB582/JMB585") and commit 20730e9b2778
> ("ahci: add 43-bit DMA address quirk for ASMedia ASM1061 controllers").
> The ASM1166 currently maps to plain board_ahci with no DMA limit.

Have you tried the same quirk, limiting DMA to 43-bits ? It is very likely that
this adapter bug is the same as the 1061.

-- 
Damien Le Moal
Western Digital Research