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: stable@vger.kernel.org Signed-off-by: Timo Sigurdsson public_timo.s@silentcreek.de Tested-by: Timo Sigurdsson public_timo.s@silentcreek.de --- Changes since v1:

- Formal changes to the commit message (Fixes and Cc lines) as suggested by Greg Kroah-Hartman and Sergei Shtylyov. 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,