DIPM is unsupported or broken on sunxi. Trying to enable the power
management policy med_power_with_dipm on an Allwinner A20 SoC based board
leads to immediate I/O errors and the attached SATA disk disappears from
the /dev filesystem. A reset (power cycle) is required to make the SATA
controller or disk work again. The A10 and A20 SoC data sheets and manuals
don't mention DIPM at all [1], so it's fair to assume that it's simply not
supported. But even if it was, it should be considered broken and best be
disabled in the ahci_sunxi driver.
[1] https://github.com/allwinner-zh/documents/tree/master/
Fixes: c5754b5220f0 ("ARM: sunxi: Add support for Allwinner SUNXi SoCs sata to ahci_platform")
Cc: <redacted>
Signed-off-by: Timo Sigurdsson <redacted>
Tested-by: Timo Sigurdsson <redacted>
---
Changes since v1:
- Formal changes to the commit message as suggested by Greg Kroah-Hartman
and Sergei Shtylyov (Fixes and Cc lines). No changes to the patch
itself.
---
drivers/ata/ahci_sunxi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/ata/ahci_sunxi.c b/drivers/ata/ahci_sunxi.c
index cb69b737cb49..56b695136977 100644
--- a/drivers/ata/ahci_sunxi.c
+++ b/drivers/ata/ahci_sunxi.c
@@ -200,7 +200,7 @@ static void ahci_sunxi_start_engine(struct ata_port *ap)
}
static const struct ata_port_info ahci_sunxi_port_info = {
- .flags = AHCI_FLAG_COMMON | ATA_FLAG_NCQ,
+ .flags = AHCI_FLAG_COMMON | ATA_FLAG_NCQ | ATA_FLAG_NO_DIPM,
.pio_mask = ATA_PIO4,
.udma_mask = ATA_UDMA6,
.port_ops = &ahci_platform_ops,--
2.26.2