libata: clean up SFF init mess

The intention of using port_mask in SFF init helpers was to eventually
support exoctic configurations such as combination of legacy and
native port on the same controller.  This never became actually
necessary and the related code always has been subtly broken one way
or the other.  Now that new init model is in place, there is no reason
to make common helpers capable of handling all corner cases.  Exotic
cases can simply dealt within LLDs as necessary.

This patch removes port_mask handling in SFF init helpers.  SFF init
helpers don't take n_ports argument and interpret it into port_mask
anymore.  All information is carried via port_info.  n_ports argument
is dropped and always two ports are allocated.  LLD can tell SFF to
skip certain port by marking it dummy.  Note that SFF code has been
treating unuvailable ports this way for a long time until recent
breakage fix from Linus and is consistent with how other drivers
handle with unavailable ports.

This fixes 1-port legacy host handling still broken after the recent
native mode fix and simplifies SFF init logic.  The following changes
are made...

* ata_pci_init_native_host() and ata_init_legacy_host() both now try
  to initialized whatever they can and mark failed ports dummy.  They
  return 0 if any port is successfully initialized.

* ata_pci_prepare_native_host() and ata_pci_init_one() now doesn't
  take n_ports argument.  All info should be specified via port_info
  array.  Always two ports are allocated.

* ata_pci_init_bmdma() exported to be used by LLDs in exotic cases.

* port_info handling in all LLDs are standardized - all port_info
  arrays are const stack variable named ppi.  Unless the second port
  is different from the first, its port_info is specified as NULL
  (tells libata that it's identical to the last non-NULL port_info).

* pata_hpt37x/hpt3x2n: don't modify static variable directly.  Make an
  on-stack copy instead as ata_piix does.

* pata_uli: It has 4 ports instead of 2.  Don't use
  ata_pci_prepare_native_host().  Allocate the host explicitly and use
  init helpers.  It's simple enough.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 11 insertions, 14 deletions

diff --git a/drivers/ata/pata_artop.c b/drivers/ata/pata_artop.c
index ef51940c3adb..9861059dd673 100644
--- a/drivers/ata/pata_artop.c
+++ b/drivers/ata/pata_artop.c
@@ -414,7 +414,7 @@ static const struct ata_port_operations artop6260_ops = {
 static int artop_init_one (struct pci_dev *pdev, const struct pci_device_id *id)
 {
         static int printed_version;
-        static struct ata_port_info info_6210 = {
+        static const struct ata_port_info info_6210 = {
                 .sht            = &artop_sht,
                 .flags          = ATA_FLAG_SLAVE_POSS | ATA_FLAG_SRST,
                 .pio_mask       = 0x1f, /* pio0-4 */
@@ -422,7 +422,7 @@ static int artop_init_one (struct pci_dev *pdev, const struct pci_device_id *id)
                 .udma_mask      = ATA_UDMA2,
                 .port_ops       = &artop6210_ops,
         };
-        static struct ata_port_info info_626x = {
+        static const struct ata_port_info info_626x = {
                 .sht            = &artop_sht,
                 .flags          = ATA_FLAG_SLAVE_POSS | ATA_FLAG_SRST,
                 .pio_mask       = 0x1f, /* pio0-4 */
@@ -430,7 +430,7 @@ static int artop_init_one (struct pci_dev *pdev, const struct pci_device_id *id)
                 .udma_mask      = ATA_UDMA4,
                 .port_ops       = &artop6260_ops,
         };
-        static struct ata_port_info info_626x_fast = {
+        static const struct ata_port_info info_626x_fast = {
                 .sht            = &artop_sht,
                 .flags          = ATA_FLAG_SLAVE_POSS | ATA_FLAG_SRST,
                 .pio_mask       = 0x1f, /* pio0-4 */
@@ -438,32 +438,30 @@ static int artop_init_one (struct pci_dev *pdev, const struct pci_device_id *id)
                 .udma_mask      = ATA_UDMA5,
                 .port_ops       = &artop6260_ops,
         };
-        struct ata_port_info *port_info[2];
-        struct ata_port_info *info = NULL;
-        int ports = 2;
+        const struct ata_port_info *ppi[] = { NULL, NULL };
 
         if (!printed_version++)
                 dev_printk(KERN_DEBUG, &pdev->dev,
                            "version " DRV_VERSION "\n");
 
         if (id->driver_data == 0) {     /* 6210 variant */
-                info = &info_6210;
+                ppi[0] = &info_6210;
+                ppi[1] = &ata_dummy_port_info;
                 /* BIOS may have left us in UDMA, clear it before libata probe */
                 pci_write_config_byte(pdev, 0x54, 0);
                 /* For the moment (also lacks dsc) */
                 printk(KERN_WARNING "ARTOP 6210 requires serialize functionality not yet supported by libata.\n");
                 printk(KERN_WARNING "Secondary ATA ports will not be activated.\n");
-                ports = 1;
         }
         else if (id->driver_data == 1)  /* 6260 */
-                info = &info_626x;
+                ppi[0] = &info_626x;
         else if (id->driver_data == 2)  { /* 6260 or 6260 + fast */
                 unsigned long io = pci_resource_start(pdev, 4);
                 u8 reg;
 
-                info = &info_626x;
+                ppi[0] = &info_626x;
                 if (inb(io) & 0x10)
-                        info = &info_626x_fast;
+                        ppi[0] = &info_626x_fast;
                 /* Mac systems come up with some registers not set as we
                    will need them */
 
@@ -484,10 +482,9 @@ static int artop_init_one (struct pci_dev *pdev, const struct pci_device_id *id)
 
         }
 
-        BUG_ON(info == NULL);
+        BUG_ON(ppi[0] == NULL);
 
-        port_info[0] = port_info[1] = info;
-        return ata_pci_init_one(pdev, port_info, ports);
+        return ata_pci_init_one(pdev, ppi);
 }
 
 static const struct pci_device_id artop_pci_tbl[] = {