ide-atapi: accomodate transfer length calculation for ide-cd

... by factoring it out of ide_cd_do_request() into a helper, as suggested by
Bart.

There should be no functionality change resulting from this patch.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
[bart: BLK_DEV_IDECD needs to select IDE_ATAPI now]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 14 insertions, 1 deletions

diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index 74273fdc8827..8884877bd2b5 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -252,6 +252,18 @@ int ide_scsi_expiry(ide_drive_t *drive)
 }
 EXPORT_SYMBOL_GPL(ide_scsi_expiry);
 
+int ide_cd_get_xferlen(struct request *rq)
+{
+        if (blk_fs_request(rq))
+                return 32768;
+        else if (blk_sense_request(rq) || blk_pc_request(rq) ||
+                         rq->cmd_type == REQ_TYPE_ATA_PC)
+                return rq->data_len;
+        else
+                return 0;
+}
+EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);
+
 /*
  * This is the usual interrupt handler which will be called during a packet
  * command.  We will transfer some of the data (as requested by the drive)
@@ -551,7 +563,7 @@ ide_startstop_t ide_issue_pc(ide_drive_t *drive, unsigned int timeout,
         struct ide_atapi_pc *pc = drive->pc;
         ide_hwif_t *hwif = drive->hwif;
         u32 tf_flags;
-        u16 bcount = 0;
+        u16 bcount;
         u8 scsi = !!(drive->dev_flags & IDE_DFLAG_SCSI);
 
         /* We haven't transferred any data yet */
@@ -560,6 +572,7 @@ ide_startstop_t ide_issue_pc(ide_drive_t *drive, unsigned int timeout,
 
         if (dev_is_idecd(drive)) {
                 tf_flags = IDE_TFLAG_OUT_NSECT | IDE_TFLAG_OUT_LBAL;
+                bcount = ide_cd_get_xferlen(hwif->hwgroup->rq);
         } else if (scsi) {
                 tf_flags = 0;
                 bcount = min(pc->req_xfer, 63 * 1024);