GitHub-Mirror/linux-bl808
2
0
Fork 0
mirror of https://github.com/Fishwaldo/linux-bl808.git synced 2025-06-17 20:25:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

ide-cd: fix DMA alignment regression

Browse source 
e5318b531b ("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>
This commit is contained in:
Borislav Petkov 2008-11-02 21:40:07 +01:00 • committed by Bartlomiej Zolnierkiewicz
parent 721d5dfe7e
commit 9bd27cba1a
1 changed files with 2 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

3
drivers/ide/ide-cd.c
View file

@ -1250,7 +1250,8 @@ static void cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
* separate masks. * separate masks.
*/ */
alignment = queue_dma_alignment(q) | q->dma_pad_mask; 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)) || object_is_on_stack(buf))
drive->dma = 0; drive->dma = 0;
} }