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/cs5530.c b/drivers/ide/pci/cs5530.c
index ef91e9d7c54..804ecabbd65 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) {