2.2.x fails to identify hard disk buffer?

Steve Snyder (swsnyder@home.com)
Sat, 30 Oct 1999 15:24:06 -0400 (EST)

I'm running Linux v2.2.13 on a Compaq Presario 1260. This machine has a
Fujitsu hard disk, model MHC2040AT. Linux says that the disk has 0KB
cache, Fujitsu says it has a 512KB buffer. What's going on here?

According to Fujitsu:

http://www.fcpa.com/cgi-bin/goFrames.cgi/product/hd/hd_mhc2040at_spec.html

According to Linux:

OPTI621X: IDE controller on PCI bus 00 dev a0
OPTI621X: not 100% native mode: will probe irqs later
ide0: BM-DMA at 0xfcf0-0xfcf7, BIOS settings: hda:pio, hdb:pio
ide1: BM-DMA at 0xfcf8-0xfcff, BIOS settings: hdc:pio, hdd:pio
hda: FUJITSU MHC2040AT, ATA DISK drive
hdc: TOSHIBA CD-ROM XM-1802B, ATAPI CDROM drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
hda: FUJITSU MHC2040AT, 3909MB w/0kB Cache, CHS=993/128/63

Some additional info:

# /sbin/hdparm -i /dev/hda

/dev/hda:

Model=FUJITSU MHC2040AT, FwRev=0818, SerialNo=01124560
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
RawCHS=7944/16/63, TrkSize=0, SectSize=0, ECCbytes=4
BuffType=0(?), BuffSize=0kB, MaxMultSect=16, MultSect=16
DblWordIO=no, maxPIO=2(fast), DMA=yes, maxDMA=0(slow)
CurCHS=993/128/63, CurSects=796917882, LBA=yes, LBAsects=8007552
tDMA={min:120,rec:120}, DMA modes: mword0 mword1 *mword2
IORDY=yes, tPIO={min:240,w/IORDY:120}, PIO modes: mode3 mode4

So...

1. Is there a distinction between the "buffer" size referenced by Fujitsu
and the "cache" size reported by Linux?

2. If in fact this disk has an onboard buffer, how can I enable it?

Thank you.
*** Steve Snyder ***

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/