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| author | Borislav Petkov <petkovbb@gmail.com> | 2008-11-02 23:40:07 +0300 |
|---|---|---|
| committer | Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> | 2008-11-02 23:40:07 +0300 |
| commit | 9bd27cba1aeacb6b12d05f4e5ed6361072f08fe0 (patch) | |
| tree | 33917b6981e58ad553a86c44c91f07b1ecb13847 | |
| parent | 721d5dfe7e516954c501d5e9d0dfab379cf4241a (diff) | |
| download | linux-9bd27cba1aeacb6b12d05f4e5ed6361072f08fe0.tar.xz | |
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>
| -rw-r--r-- | drivers/ide/ide-cd.c | 3 |
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) * separate masks. */ alignment = queue_dma_alignment(q) | q->dma_pad_mask; - if ((unsigned long)buf & alignment || rq->data_len & alignment + if ((unsigned long)buf & alignment + || rq->data_len & q->dma_pad_mask || object_is_on_stack(buf)) drive->dma = 0; } |