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>

1 files changed, 2 insertions, 2 deletions

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);
         }