ahci_sunxi: Make AHCI_HFLAG_NO_PMP flag configurable with a module option
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@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/ata/ahci_sunxi.c b/drivers/ata/ahci_sunxi.c
index e44d675..b5aedca 100644
--- a/drivers/ata/ahci_sunxi.c
+++ b/drivers/ata/ahci_sunxi.c
@@ -27,6 +27,12 @@
#include <linux/regulator/consumer.h>
#include "ahci.h"
+/* Insmod parameters */
+static bool enable_pmp;
+module_param(enable_pmp, bool, 0);
+MODULE_PARM_DESC(enable_pmp,
+ "Enable support for sata port multipliers, only use if you use a pmp!");
+
#define AHCI_BISTAFR 0x00a0
#define AHCI_BISTCR 0x00a4
#define AHCI_BISTFCTR 0x00a8
@@ -184,7 +190,15 @@
goto disable_resources;
hpriv->flags = AHCI_HFLAG_32BIT_ONLY | AHCI_HFLAG_NO_MSI |
- AHCI_HFLAG_NO_PMP | AHCI_HFLAG_YES_NCQ;
+ AHCI_HFLAG_YES_NCQ;
+
+ /*
+ * The sunxi sata controller seems to be unable to successfully do a
+ * soft reset if no pmp is attached, so disable pmp use unless
+ * requested, otherwise directly attached disks do not work.
+ */
+ if (!enable_pmp)
+ hpriv->flags |= AHCI_HFLAG_NO_PMP;
rc = ahci_platform_init_host(pdev, hpriv, &ahci_sunxi_port_info);
if (rc)