ahci: disable MSI instead of NCQ on Samsung pci-e SSDs on macbooks

Samsung pci-e SSDs on macbooks failed miserably on NCQ commands, so
67809f85d31e ("ahci: disable NCQ on Samsung pci-e SSDs on macbooks")
disabled NCQ on them.  It turns out that NCQ is fine as long as MSI is
not used, so let's turn off MSI and leave NCQ on.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=60731
Tested-by: <dorin@i51.org>
Tested-by: Imre Kaloz <kaloz@openwrt.org>
Cc: stable@vger.kernel.org
Fixes: 67809f85d31e ("ahci: disable NCQ on Samsung pci-e SSDs on macbooks")

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 5f039f1910677ff45d59cb4f7c0812f84f1dac23..ef4b647b3ed2b006349839dec8537378c4a2fecd 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -60,6 +60,7 @@ enum board_ids {
        /* board IDs by feature in alphabetical order */
        board_ahci,
        board_ahci_ign_iferr,
+       board_ahci_nomsi,
        board_ahci_noncq,
        board_ahci_nosntf,
        board_ahci_yes_fbs,
@@ -121,6 +122,13 @@ static const struct ata_port_info ahci_port_info[] = {
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &ahci_ops,
        },
+       [board_ahci_nomsi] = {
+               AHCI_HFLAGS     (AHCI_HFLAG_NO_MSI),
+               .flags          = AHCI_FLAG_COMMON,
+               .pio_mask       = ATA_PIO4,
+               .udma_mask      = ATA_UDMA6,
+               .port_ops       = &ahci_ops,
+       },
        [board_ahci_noncq] = {
                AHCI_HFLAGS     (AHCI_HFLAG_NO_NCQ),
                .flags          = AHCI_FLAG_COMMON,
@@ -475,10 +483,10 @@ static const struct pci_device_id ahci_pci_tbl[] = {
        { PCI_VDEVICE(ASMEDIA, 0x0612), board_ahci },   /* ASM1062 */
 
        /*
-        * Samsung SSDs found on some macbooks.  NCQ times out.
-        * https://bugzilla.kernel.org/show_bug.cgi?id=60731
+        * Samsung SSDs found on some macbooks.  NCQ times out if MSI is
+        * enabled.  https://bugzilla.kernel.org/show_bug.cgi?id=60731
         */
-       { PCI_VDEVICE(SAMSUNG, 0x1600), board_ahci_noncq },
+       { PCI_VDEVICE(SAMSUNG, 0x1600), board_ahci_nomsi },
 
        /* Enmotus */
        { PCI_DEVICE(0x1c44, 0x8000), board_ahci },