1 files changed, 12 insertions, 5 deletions

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index d6667c36568c..e12d60278210 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1191,12 +1191,17 @@ static ide_startstop_t cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
         info->dma = 0;
 
         /* sg request */
-        if (rq->bio) {
-                int mask = drive->queue->dma_alignment;
-                unsigned long addr =
-                        (unsigned long)page_address(bio_page(rq->bio));
+        if (rq->bio || ((rq->cmd_type == REQ_TYPE_ATA_PC) && rq->data_len)) {
+                struct request_queue *q = drive->queue;
+                unsigned int alignment;
+                unsigned long addr;
                 unsigned long stack_mask = ~(THREAD_SIZE - 1);
 
+                if (rq->bio)
+                        addr = (unsigned long)bio_data(rq->bio);
+                else
+                        addr = (unsigned long)rq->data;
+
                 info->dma = drive->using_dma;
 
                 /*
@@ -1205,7 +1210,8 @@ static ide_startstop_t cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
                  * NOTE! The "len" and "addr" checks should possibly have
                  * separate masks.
                  */
-                if ((rq->data_len & 15) || (addr & mask))
+                alignment = queue_dma_alignment(q) | q->dma_pad_mask;
+                if (addr & alignment || rq->data_len & alignment)
                         info->dma = 0;
 
                 if (!((addr & stack_mask) ^
@@ -1877,6 +1883,7 @@ static int ide_cdrom_setup(ide_drive_t *drive)
 
         blk_queue_prep_rq(drive->queue, ide_cdrom_prep_fn);
         blk_queue_dma_alignment(drive->queue, 31);
+        blk_queue_update_dma_pad(drive->queue, 15);
         drive->queue->unplug_delay = (1 * HZ) / 1000;
         if (!drive->queue->unplug_delay)
                 drive->queue->unplug_delay = 1;