how to enable cache flushes for hard disk?

Tito farmatito at tiscali.it
Tue May 22 11:35:16 UTC 2007


On Tuesday 22 May 2007 10:34:43 kaimi wrote:
> Another question, on my pc, the hd supports cache flushes, it shows:
> 
> [root at localhost linux-2.6.20-dm]# hdparm -T /dev/hdb
> 
> /dev/hdb:
>  Timing cached reads:   3344 MB in  2.00 seconds = 1671.72 MB/sec
> 
> and my target board does not support cache flushed, it shows:
> [root at test tmp]# ./hdparm -T /dev/hda
> 
> /dev/hda:
>  Timing cached reads:    68 MB in  2.04 seconds =  33.30 MB/sec
> 
> I don't know if this feature is the inducement, I want to disable this
> feature on pc, what's the command? thanks

Maybe man hdparm:


       -W     Disable/enable  the  IDE  drive´s write-caching feature (default
              state is undeterminable; manufacturer/model specific).

ciao,
Tito
> 
> On 5/22/07, kaimi <dishui at gmail.com> wrote:
> >
> > hi,all
> >     I want to enable cache flushes for my hd on s3c2410 & linux-2.6.20,
> > ide_id_has_flush_cache() return 0 because cfs_enable_2 is 0x201, while it
> > needs 0x3000, I found out that 0x201 was from 512 bytes of id
> > info,implemented in static void ata_input_data(ide_drive_t *drive, void
> > *buffer, u32 wcount)
> > the question is, does it mean my hd does not support cache flush on hw
> > layer? if not, how to enable?
> > thanks for the coming help!
> >
> > Rgrds
> > Kaimi
> >
> >
> 





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