ide: check drive->present in ide_get_paired_drive()

* Change ide_get_paired_drive() to return NULL if peer device
  is not present and update all users accordingly.

While at it:

* ide_get_paired_drive() -> ide_get_pair_dev()

* Use ide_get_pair_dev() in cs5530.c, sc1200.c and via82cxxx.c.

There should be no functional changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

6 files changed, 12 insertions, 12 deletions

diff --git a/drivers/ide/pci/cs5530.c b/drivers/ide/pci/cs5530.c
index ef91e9d7c54f..804ecabbd65f 100644
--- a/drivers/ide/pci/cs5530.c
+++ b/drivers/ide/pci/cs5530.c
@@ -81,11 +81,11 @@ static void cs5530_set_pio_mode(ide_drive_t *drive, const u8 pio)
 static u8 cs5530_udma_filter(ide_drive_t *drive)
 {
         ide_hwif_t *hwif = drive->hwif;
-        ide_drive_t *mate = &hwif->drives[(drive->dn & 1) ^ 1];
+        ide_drive_t *mate = ide_get_pair_dev(drive);
         u16 *mateid = mate->id;
         u8 mask = hwif->ultra_mask;
 
-        if (mate->present == 0)
+        if (mate == NULL)
                 goto out;
 
         if (ata_id_has_dma(mateid) && __ide_dma_bad_drive(mate) == 0) {
diff --git a/drivers/ide/pci/cs5535.c b/drivers/ide/pci/cs5535.c
index dd3dc23af995..707d2e182552 100644
--- a/drivers/ide/pci/cs5535.c
+++ b/drivers/ide/pci/cs5535.c
@@ -80,12 +80,12 @@ static void cs5535_set_speed(ide_drive_t *drive, const u8 speed)
 
         /* Set the PIO timings */
         if (speed < XFER_SW_DMA_0) {
-                ide_drive_t *pair = ide_get_paired_drive(drive);
+                ide_drive_t *pair = ide_get_pair_dev(drive);
                 u8 cmd, pioa;
 
                 cmd = pioa = speed - XFER_PIO_0;
 
-                if (pair->present) {
+                if (pair) {
                         u8 piob = ide_get_best_pio_mode(pair, 255, 4);
 
                         if (piob < cmd)
diff --git a/drivers/ide/pci/opti621.c b/drivers/ide/pci/opti621.c
index e28e672ddafc..e913da479808 100644
--- a/drivers/ide/pci/opti621.c
+++ b/drivers/ide/pci/opti621.c
@@ -137,7 +137,7 @@ static u8 read_reg(int reg)
 static void opti621_set_pio_mode(ide_drive_t *drive, const u8 pio)
 {
         ide_hwif_t *hwif = drive->hwif;
-        ide_drive_t *pair = ide_get_paired_drive(drive);
+        ide_drive_t *pair = ide_get_pair_dev(drive);
         unsigned long flags;
         u8 tim, misc, addr_pio = pio, clk;
 
@@ -153,7 +153,7 @@ static void opti621_set_pio_mode(ide_drive_t *drive, const u8 pio)
 
         drive->drive_data = XFER_PIO_0 + pio;
 
-        if (pair->present) {
+        if (pair) {
                 if (pair->drive_data && pair->drive_data < drive->drive_data)
                         addr_pio = pair->drive_data - XFER_PIO_0;
         }
diff --git a/drivers/ide/pci/sc1200.c b/drivers/ide/pci/sc1200.c
index 695cc9742048..37326d2205b8 100644
--- a/drivers/ide/pci/sc1200.c
+++ b/drivers/ide/pci/sc1200.c
@@ -104,11 +104,11 @@ static void sc1200_tunepio(ide_drive_t *drive, u8 pio)
 static u8 sc1200_udma_filter(ide_drive_t *drive)
 {
         ide_hwif_t *hwif = drive->hwif;
-        ide_drive_t *mate = &hwif->drives[(drive->dn & 1) ^ 1];
+        ide_drive_t *mate = ide_get_pair_dev(drive);
         u16 *mateid = mate->id;
         u8 mask = hwif->ultra_mask;
 
-        if (mate->present == 0)
+        if (mate == NULL)
                 goto out;
 
         if (ata_id_has_dma(mateid) && __ide_dma_bad_drive(mate) == 0) {
diff --git a/drivers/ide/pci/siimage.c b/drivers/ide/pci/siimage.c
index 7b5bd8729f64..83c36e6035fa 100644
--- a/drivers/ide/pci/siimage.c
+++ b/drivers/ide/pci/siimage.c
@@ -245,7 +245,7 @@ static void sil_set_pio_mode(ide_drive_t *drive, u8 pio)
 
         ide_hwif_t *hwif        = HWIF(drive);
         struct pci_dev *dev     = to_pci_dev(hwif->dev);
-        ide_drive_t *pair       = ide_get_paired_drive(drive);
+        ide_drive_t *pair       = ide_get_pair_dev(drive);
         u32 speedt              = 0;
         u16 speedp              = 0;
         unsigned long addr      = siimage_seldev(drive, 0x04);
@@ -259,7 +259,7 @@ static void sil_set_pio_mode(ide_drive_t *drive, u8 pio)
         u8 unit                 = drive->select.b.unit;
 
         /* trim *taskfile* PIO to the slowest of the master/slave */
-        if (pair->present) {
+        if (pair) {
                 u8 pair_pio = ide_get_best_pio_mode(pair, 255, 4);
 
                 if (pair_pio < tf_pio)
diff --git a/drivers/ide/pci/via82cxxx.c b/drivers/ide/pci/via82cxxx.c
index 94fb9ab3223f..9cb531dc905a 100644
--- a/drivers/ide/pci/via82cxxx.c
+++ b/drivers/ide/pci/via82cxxx.c
@@ -154,7 +154,7 @@ static void via_set_speed(ide_hwif_t *hwif, u8 dn, struct ide_timing *timing)
 static void via_set_drive(ide_drive_t *drive, const u8 speed)
 {
         ide_hwif_t *hwif = drive->hwif;
-        ide_drive_t *peer = hwif->drives + (~drive->dn & 1);
+        ide_drive_t *peer = ide_get_pair_dev(drive);
         struct pci_dev *dev = to_pci_dev(hwif->dev);
         struct ide_host *host = pci_get_drvdata(dev);
         struct via82cxxx_dev *vdev = host->host_priv;
@@ -173,7 +173,7 @@ static void via_set_drive(ide_drive_t *drive, const u8 speed)
 
         ide_timing_compute(drive, speed, &t, T, UT);
 
-        if (peer->present) {
+        if (peer) {
                 ide_timing_compute(peer, peer->current_speed, &p, T, UT);
                 ide_timing_merge(&p, &t, &t, IDE_TIMING_8BIT);
         }