More disk issues (DMA/VIA)

[Aaron <aaron@core-dev.com>]

*sigh*

After a lot of coaching from everyone here it was decided that ext3
probably has nothing at all to do with my disk performance problems.
More likely it was that DMA is not enabled on my drive. This is
true, as shown...

root@chimera:~# hdparm -d /dev/hdb

/dev/hdb:
 using_dma    =  0 (off)

But, unfortunately, I can't turn it on, either:

root@chimera:~# hdparm -d1 /dev/hdb

/dev/hdb:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma    =  0 (off)

Here is the whole dump from hdparm -i:

root@chimera:~# hdparm -i /dev/hdb

/dev/hdb:

 Model=Maxtor 6Y200L6, FwRev=YAR41VW0, SerialNo=M0000000000000000000
 Config={ Fixed }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
 BuffType=DualPortCache, BuffSize=7936kB, MaxMultSect=16, MultSect=16
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=268435455
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes: pio0 pio1 pio2 pio3 pio4 
 DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 *udma5
udma6 
 AdvancedPM=yes: disabled (255) WriteCache=enabled
 Drive Supports : ataATA-1 ATA-2 ATA-3 ATA-4 ATA-5 ATA-6 ATA-7 

It looks like the drive supports it... I believe that because it's
brand spankin' new and 200 gigs. After surfing a lot of other mailing list archives and groups online, it looks like this information is also pretty important:

root@chimera:~# lspci -v
00:00.0 Host bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133]
(rev 03)
        Subsystem: ABIT Computer Corp.: Unknown device a401
        Flags: bus master, medium devsel, latency 0
        Memory at d0000000 (32-bit, prefetchable) [size=64M]
        Capabilities: [a0] AGP version 2.0
        Capabilities: [c0] Power Management version 2

00:01.0 PCI bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133
AGP] (prog-if 00 [Normal decode])
        Flags: bus master, 66Mhz, medium devsel, latency 0
        Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
        I/O behind bridge: 00009000-00009fff
        Memory behind bridge: d8000000-d9ffffff
        Prefetchable memory behind bridge: d4000000-d7ffffff

00:07.0 ISA bridge: VIA Technologies, Inc. VT82C686 [Apollo Super
South] (rev 40)
        Subsystem: VIA Technologies, Inc. VT82C686/A PCI to ISA Bridge
        Flags: bus master, stepping, medium devsel, latency 0
        Capabilities: [c0] Power Management version 2

00:07.1 IDE interface: VIA Technologies, Inc. Bus Master IDE (rev 06)
(prog-if 8a [Master SecP PriP])
        Flags: bus master, medium devsel, latency 32
        I/O ports at a000 [size=16]
        Capabilities: [c0] Power Management version 2

[snip]

I'm running:

root@chimera:~# uname -a
Linux chimera 2.4.21 #4 Mon Jun 23 17:44:47 EDT 2003 i686 unknown

And if you want a dump of my dmesg or my .config, let me know. I have
enabled everything in my kernel that seemed relevant to VIA or DMA,
including "VIA82CXXX chipset support" (although that doesn't match my
chipset model, which I suspect to be close to my problem), and "PCI IDE
chipset support", "Generic PCI bus-master DMA support", and "Use PCI
DMA by default when available."

So does my VIA chipset have support? I'd love to have UDMA...

Thanks!

-- 
Aaron Bieber
-
Graphic Design // Web Design
http://www.core-dev.com/
aaron@core-dev.com