[PATCH 6.6 024/166] ata: ahci: force 32-bit DMA for JMicron JMB582/JMB585

Greg Kroah-Hartman
2026-04-24T13:34:27Z

From: Arthur Husband <artmoty@gmail.com>

[ Upstream commit 105c42566a550e2d05fc14f763216a8765ee5d0e ]

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 20730e9b2778 ("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>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/ata/ahci.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 98104d0b842bd..9d59e6e2d63ba 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -60,6 +60,7 @@ enum board_ids {
/* board IDs for specific chipsets in alphabetical order */
board_ahci_al,
board_ahci_avn,
+ board_ahci_jmb585,
board_ahci_mcp65,
board_ahci_mcp77,
board_ahci_mcp89,
@@ -199,6 +200,15 @@ static const struct ata_port_info ahci_port_info[] = {
.udma_mask = ATA_UDMA6,
.port_ops = &ahci_avn_ops,
},
+ /* JMicron JMB582/585: 64-bit DMA is broken, force 32-bit */
+ [board_ahci_jmb585] = {
+ AHCI_HFLAGS (AHCI_HFLAG_IGN_IRQ_IF_ERR |
+ AHCI_HFLAG_32BIT_ONLY),
+ .flags = AHCI_FLAG_COMMON,
+ .pio_mask = ATA_PIO4,
+ .udma_mask = ATA_UDMA6,
+ .port_ops = &ahci_ops,
+ },
[board_ahci_mcp65] = {
AHCI_HFLAGS (AHCI_HFLAG_NO_FPDMA_AA | AHCI_HFLAG_NO_PMP |
AHCI_HFLAG_YES_NCQ),
@@ -432,6 +442,10 @@ static const struct pci_device_id ahci_pci_tbl[] = {
/* Elkhart Lake IDs 0x4b60 & 0x4b62 https://sata-io.org/product/8803 not tested yet */
{ PCI_VDEVICE(INTEL, 0x4b63), board_ahci_low_power }, /* Elkhart Lake AHCI */

+ /* JMicron JMB582/585: force 32-bit DMA (broken 64-bit implementation) */
+ { PCI_VDEVICE(JMICRON, 0x0582), board_ahci_jmb585 },
+ { PCI_VDEVICE(JMICRON, 0x0585), board_ahci_jmb585 },
+
/* JMicron 360/1/3/5/6, match class to avoid IDE function */
{ PCI_VENDOR_ID_JMICRON, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
PCI_CLASS_STORAGE_SATA_AHCI, 0xffffff, board_ahci_ign_iferr },
--
2.53.0