aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/ide/ide-cd.c
diff options
context:
space:
mode:
authorBorislav Petkov <petkovbb@gmail.com>2008-11-02 15:40:07 -0500
committerBartlomiej Zolnierkiewicz <bzolnier@gmail.com>2008-11-02 15:40:07 -0500
commit9bd27cba1aeacb6b12d05f4e5ed6361072f08fe0 (patch)
tree33917b6981e58ad553a86c44c91f07b1ecb13847 /drivers/ide/ide-cd.c
parent721d5dfe7e516954c501d5e9d0dfab379cf4241a (diff)
ide-cd: fix DMA alignment regression
e5318b531b008c79d2a0c0df06a7b8628da38e2f ("ide: use the dma safe check for REQ_TYPE_ATA_PC") introduced a regression which caused some ATAPI drives to turn off DMA for REQ_TYPE_BLOCK_PC commands while burning and thus degrading performance and ultimately causing an excessive amount of underruns. The issue is documented also in: http://bugzilla.kernel.org/show_bug.cgi?id=11742. Signed-off-by: Borislav Petkov <petkovbb@gmail.com> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Tested-by: Valerio Passini <valerio.passini@unicam.it> [bart: fixup patch description per comments from Sergei Shtylyov] Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Diffstat (limited to 'drivers/ide/ide-cd.c')
-rw-r--r--drivers/ide/ide-cd.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 48b5eda3ab41..42ab6d8715f2 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1250,7 +1250,8 @@ static void cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
1250 * separate masks. 1250 * separate masks.
1251 */ 1251 */
1252 alignment = queue_dma_alignment(q) | q->dma_pad_mask; 1252 alignment = queue_dma_alignment(q) | q->dma_pad_mask;
1253 if ((unsigned long)buf & alignment || rq->data_len & alignment 1253 if ((unsigned long)buf & alignment
1254 || rq->data_len & q->dma_pad_mask
1254 || object_is_on_stack(buf)) 1255 || object_is_on_stack(buf))
1255 drive->dma = 0; 1256 drive->dma = 0;
1256 } 1257 }