Bug 47597 - UDMA not available with IBM Deskstar disks and K7T266 PRO motherboard
Summary: UDMA not available with IBM Deskstar disks and K7T266 PRO motherboard
Alias: None
Product: Red Hat Linux
Classification: Retired
Component: kernel
Version: 7.1
Hardware: i686
OS: Linux
Target Milestone: ---
Assignee: Arjan van de Ven
QA Contact: Brock Organ
Depends On:
TreeView+ depends on / blocked
Reported: 2001-07-06 07:58 UTC by Pawel Salek
Modified: 2007-04-18 16:34 UTC (History)
0 users

Clone Of:
Last Closed: 2001-11-17 23:08:16 UTC

Attachments (Terms of Use)

Description Pawel Salek 2001-07-06 07:58:06 UTC
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux 2.4.3-12 i686; en-US; rv:0.9.1)

Description of problem:
kernel-2.4.2-2 provided UDMA(33) support with IBM Deskstar 60GXP disks and
Microstar K7T266 PRO motherboard based on VIA KT266 chipset. After kernel
upgrade to kernel-2.4.3-12, only PIO modes were available.

How reproducible:

Steps to Reproduce:
1.install kernel-2.4.3-12 on specified hardware.
2.run hdparm -d1 /dev/hda

Actual Results:  hdparm says: operation not permitted.

Expected Results:  hdparm should report mode changed to DMA.

Additional info:

I tested the specified harware with DMA enabled under heavy momory and IO
load (quantum chemistry chalculations: single test duration > 24h; several
tests have been performed) and the box survived. Box has two disks and runs
software RAID0 (striping) on them. BIOS is original 1.0 version (BIOS
upgrades require Win32 and I had to refrain). I am aware that some/many VIA
chipsets are buggy but this setup seems to be an exception.

The relevant dmesg output for 2.4.2-2 is:

VP_IDE: VIA vt8233 (rev 00) IDE UDMA100 controller on pci00:11.1
    ide0: BM-DMA at 0xff00-0xff07, BIOS settings: hda:DMA, hdb:DMA
    ide1: BM-DMA at 0xff08-0xff0f, BIOS settings: hdc:pio, hdd:pio
hda: IC35L040AVER07-0, ATA DISK drive
hdb: IC35L040AVER07-0, ATA DISK drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
hda: 80418240 sectors (41174 MB) w/1916KiB Cache, CHS=5005/255/63, UDMA(33)
hdb: 80418240 sectors (41174 MB) w/1916KiB Cache, CHS=5005/255/63, UDMA(33)

I have actually tried forcing UDMA(100) with 2.4.2-2 (append="ide0=ata66"
in /etc/lilo.conf) but have not had yet time to test it as thoroughly as

If you need more information, just ask.

Comment 1 Arjan van de Ven 2001-07-06 09:46:18 UTC
Could you check if the drive isn't already in DMA mode?
cat /proc/ide/hda/settings
should give that info.

Comment 2 Pawel Salek 2001-07-06 09:58:46 UTC
I do not have 2.4.3-12 running right now but I am positive
hdparm /dev/hda
reported that DMA was off. I hope this is equivalent. If not, I can reboot the
box and check it.

Comment 3 Arjan van de Ven 2001-07-06 10:03:12 UTC
hdparm should give you the same indeed (it uses the same interface).
The only change between 2.4.2-2 and 2.4.3-12 in this area is that 2.4.2-2
would disable DMA on ABIT KT7 boards due to a > 95% "corrupts data" rate,
while 2.4.3-12 has the official VIA workaround for the bug and doesn't have
this restriction anymore. This seems to be the opposite of what you're
/me wonders.

Comment 4 Pawel Salek 2001-07-06 10:19:25 UTC
For the record: I tried kernel-2.4.5-10.src.rpm from rawhide and it could not
enable DMA, neither.

Comment 5 Pawel Salek 2001-07-06 11:38:27 UTC
I have recalled one more thing: hdparm crashed with certain option combination
(I think it was -X66) and kernel-2.4.3-12, generating an oops:

Jul  5 17:29:05 xi kernel: ide0: Speed warnings UDMA 3/4/5 is not functional. 
Jul  5 17:29:27 xi kernel: divide error: 0000 
xi kernel: CPU:    0 
xi kernel: EIP:    0010:[via_set_drive+142/352] 
xi kernel: EIP:    0010:[<c01983ce>] 
xi kernel: EFLAGS: 00010246 
xi kernel: eax: 000003e8   ebx: c02d2960   ecx: 00000040   edx: 00000000 
xi kernel: esi: c02d2960   edi: ee885ef8   ebp: c02d2960   esp: ee885e78 
xi kernel: ds: 0018   es: 0018   ss: 0018 
xi kernel: Process hdparm (pid: 943, stackpage=ee885000) 
xi kernel: Stack: c02d2a94 40000000 00000000 00000000 00000000 00000000 00000000
xi kernel:        ee885ef4 ee885e08 00000000 00000000 00000000 00000001 c02d2960
xi kernel:        ee885ef8 bffff7cc c02d2960 c02d2960 ee885ef8 bffff7cc c018bd91
xi kernel: Call Trace: [ide_ioctl+2289/3376] [write_chan+492/528]
[blkdev_ioctl+38/64] [sys_ioctl+375/400] [system_call+51/56]  
xi kernel: Call Trace: [<c018bd91>] [<c0170dec>] [<c0139656>] [<c013fbe7>]
xi kernel:  
xi kernel: Code: f7 35 34 49 2d c0 89 c7 a1 28 49 2d c0 0f b7 40 08 83 e0 07

Comment 6 Pawel Salek 2001-08-03 09:22:02 UTC
For the record, kernel-2.4.6-3.1 of Roswell does not fix this problem. 
I wonder if it matters: this is straight KT7 motherboard, it is K7T266 based on
different chipset, as far as I can tell.

Also, I have been using it under heavy load for a month with ide0=ata66 enabled
and experienced no problems at all (well, no problems that seemed to be related).

Comment 7 Pawel Salek 2001-11-17 23:08:10 UTC
2.4.9-13 kernels appear to work just fine. This report can be closed as far I am
concerned with resolution as ERRATA.

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