Re: [PATCH v2] ata: ahci: force 32-bit DMA for JMicron JMB582/JMB585

[Niklas Cassel <cassel@kernel.org>]

Hello Arthur,

On Fri, Apr 03, 2026 at 03:53:14PM -0700, Arthur Husband wrote:
> The JMicron JMB585 (and JMB582) SATA controllers advertise 64-bit DMA
> support via the S64A bit in the AHCI CAP register, but their 64-bit DMA
> implementation is defective. Under sustained I/O, DMA transfers targeting
> addresses above 4GB silently corrupt data -- writes land at incorrect
> memory addresses with no errors logged.
> 
> The failure pattern is similar to the ASMedia ASM1061 (commit
> 2073d0e9b2778 ("ahci: add 43-bit DMA address quirk for ASMedia ASM1061
> controllers")), which also falsely advertised full 64-bit DMA support.
> However, the JMB585 requires a stricter 32-bit DMA mask rather than
> 43-bit, as corruption occurs with any address above 4GB.
> 
> On the Minisforum N5 Pro specifically, the combination of the JMB585's
> broken 64-bit DMA with the AMD Family 1Ah (Strix Point) IOMMU causes
> silent data corruption that is only detectable via checksumming
> filesystems (BTRFS/ZFS scrub). The corruption occurs when 32-bit IOVA
> space is exhausted and the kernel transparently switches to 64-bit DMA
> addresses.
> 
> Add device-specific PCI ID entries for the JMB582 (0x0582) and JMB585
> (0x0585) before the generic JMicron class match, using a new board type
> that combines AHCI_HFLAG_IGN_IRQ_IF_ERR (preserving existing behavior)
> with AHCI_HFLAG_32BIT_ONLY to force 32-bit DMA masks.
> 
> Signed-off-by: Arthur Husband <artmoty@gmail.com>
> ---

You have sent two different V2 patches, however both of them fail to apply:

error: patch fragment without header at line 18: @@ -115,6 +116,14 @@ static const struct ata_port_info ahci_port_info[] = {
error: could not build fake ancestor
Patch failed at 0001 ata: ahci: force 32-bit DMA for JMicron JMB582/JMB585


>  drivers/ata/ahci.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
> index XXXXXXX..XXXXXXX 100644

I think the problem is that you have index XXXXXXX..XXXXXXX.

The XXXXXXX should be pre- and post-image blob object SHA1s, e.g.:
index ad798e5246b49..3b65df914ebbe 100644

Please use git-format-patch to generate your patch and send a V3.


Kind regards,
Niklas