On Fri, Nov 14, 2014 at 04:09:31PM +0100, Hans de Goede wrote: > The use of the AHCI_HFLAG_NO_PMP flag is something which we inherited from > the Allwinner android kernel sources, and I've always wanted to test if this > is really necessary. > > So recently I've bought a sata port multiplexer, and I've given this a test > spin on both A10 and A20 devices, and it seems to work fine: > > [ 2.154456] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300) > [ 2.161092] ata1.15: Port Multiplier 1.2, 0x197b:0x0325 r0, 5 ports, feat 0x5/0xf > [ 2.175511] ata1.00: hard resetting link > [ 2.524929] ata1.00: SATA link up 3.0 Gbps (SStatus 123 SControl 320) > [ 2.531430] ata1.01: hard resetting link > [ 2.974465] ata1.01: link resume succeeded after 1 retries > [ 3.094932] ata1.01: SATA link up 3.0 Gbps (SStatus 123 SControl 300) > [ 3.101431] ata1.02: hard resetting link > [ 4.174466] ata1.02: failed to resume link (SControl 0) > [ 4.180065] ata1.02: SATA link down (SStatus 0 SControl 0) > (and the same for links 3 and 4) > > Once the NO_PMP flag is removed it correctly sees the 2 disks which I've > attached, and I can mount and use them just fine. > > Unfortunately when I then directly attached a disk to the sata port on the > sunxi SoC, and booted a kernel without the AHCI_HFLAG_NO_PMP flag, it would > not recognize that disk. > > It turns out that the sata controller in the sunxi SoCs fails to handle > soft-resets issued to directly attached disks, and when pmp support is > enabled the kernel will always issue a soft-reset. > > So add a module parameter to enable pmp usage, and default this to off, so > that directly attached disks keep working normally. > > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Applied to libata/for-3.19. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
