path: root/Documentation
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authorBartlomiej Zolnierkiewicz <bzolnier@gmail.com>2008-01-26 20:13:09 +0100
committerBartlomiej Zolnierkiewicz <bzolnier@gmail.com>2008-01-26 20:13:09 +0100
commit9e47be0c97f7357b80e91dc0632e9cce2eb025e0 (patch)
tree7047b2b3c9ac094b801d376e4bbb95292b1962ac /Documentation
parentide: add ide_busy_sleep() helper (diff)
ide: remove broken disk byte-swapping support
Remove broken disk byte-swapping support: - it can cause a data corruption on SMP (or if using PREEMPT on UP) - all data coming from disk are byte-swapped by taskfile_*_data() which results in incorrect identify data being reported by /proc/ide/ and IOCTLs - "hdx=bswap/byteswap" kernel parameter has been broken on m68k host drivers (including Atari/Q40 ones) since 2.5.x days (because of 'hwif' zero-ing) - byte-swapping is limited to PIO transfers (for working with TiVo disks on x86 machines using user-space solutions or dm-byteswap should result in much better performance because DMA can be used) For previous discussions please see: http://www.ussg.iu.edu/hypermail/linux/kernel/0201.0/0768.html http://lkml.org/lkml/2004/2/28/111 [ I have dm-byteswap device mapper target if somebody is interested (patch is for 2.6.4 though but I'll dust it off if needed). ] Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Diffstat (limited to 'Documentation')
1 files changed, 0 insertions, 4 deletions
diff --git a/Documentation/ide.txt b/Documentation/ide.txt
index b29ccb43d6cc..94e2e3b9e77f 100644
--- a/Documentation/ide.txt
+++ b/Documentation/ide.txt
@@ -244,10 +244,6 @@ Summary of ide driver parameters for kernel command line
"hdx=nodma" : disallow DMA
- "hdx=swapdata" : when the drive is a disk, byte swap all data
- "hdx=bswap" : same as above..........
"hdx=scsi" : the return of the ide-scsi flag, this is useful for
allowing ide-floppy, ide-tape, and ide-cdrom|writers
to use ide-scsi emulation on a device specific option.