[linux-usb-devel] 2.6: USB disk unusable level of data corruption

[linux-usb-devel] 2.6: USB disk unusable level of data corruption

Post by David Brow » Sun, 06 Feb 2005 06:00:14



I don't think so, but there are problems that appear in some
hardware configs and not others. Many folk report no problems;
a (very) few report nothing but.

If you've verified this on 2.6.10, then you certainly have
have the ehci-hcd (re)queueing race fix that has made a big
difference for some folk. I don't know of any other issues
in that driver that could explain usb-storage problems.

What hardware config do you have?

- Whose EHCI controller and revision? I've never had
good luck with VIA VT6202. ("lspci -v".)

- Whose USB storage adapter? ("lsusb -v", or in this
case the /proc/bus/usb/devices entry would be ok.)
GeneSys adapters have been the most problematic,
but they're hardly the only ones with quirks.

Thing is, that driver stack isn't especially thin: SCSI isn't
the top, and it's got usb-storage, usbcore, and a USB HCD under
it. That makes it harder to track down root causes, even when
there is just a single one and it's in those drivers (rather
than being hardware misbehavior).

- Dave
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to XXXX@XXXXX.COM
More majordomo info at http://www.yqcomputer.com/
Please read the FAQ at http://www.yqcomputer.com/
 
 
 

[linux-usb-devel] 2.6: USB disk unusable level of data corruption

Post by Alan Ster » Sun, 06 Feb 2005 06:30:19


Right now we have no reason to believe there's anything wrong with the USB
stack or the usb-storage/SCSI drivers. A few other people have also
reported data corruption at about the same level as you; we've only been
able to trace a couple of them to software errors. And those generally
involved a higher error rate than you're seeing.

The most likely explanation seems to be hardware problems. Particularly
for high-speed USB devices, 2.6 drives the hardware much closer to the
limit than 2.4 or Windows (to judge by the problem reports we've seen).
One case came up just a couple of days ago, in which this sort of data
corruption was definitively traced to a known erratum in the peripheral's
USB interface. (The controller chip was an old revision which has been
supplanted, but who knows what sort of hardware lurks in the hearts of
commercial drives?)

Alan Stern

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to XXXX@XXXXX.COM
More majordomo info at http://www.yqcomputer.com/
Please read the FAQ at http://www.yqcomputer.com/

 
 
 

[linux-usb-devel] 2.6: USB disk unusable level of data corruption

Post by David Brow » Sun, 06 Feb 2005 07:10:07


Agreed ... though limiting usb-storage I/O requests to 64 KB does tend to
mask that difference. Some network adapters get better throughput than
Windows, too. URB queueing does the trick ... not really usable on 2.4
kernels, but the costs on 2.6 seem substantially lower than on Windows.



If you're thinking of that net2280 issue, that erratum was specific
to full speed modes, and never appeared at high speed. Also, that chip
wouldn't be used in mass market IDE adapters. (Too pricey compared to
the custom chips that have no need for a CPU or PCI.)

But the point is good: it's easy for hardware to have bugs there.

- Dave



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to XXXX@XXXXX.COM
More majordomo info at http://www.yqcomputer.com/
Please read the FAQ at http://www.yqcomputer.com/
 
 
 

[linux-usb-devel] 2.6: USB disk unusable level of data corruption

Post by John Stoff » Sun, 06 Feb 2005 09:50:08


David> I don't think so, but there are problems that appear in some
David> hardware configs and not others. Many folk report no problems;
David> a (very) few report nothing but.

This is just a chime in to let people know others are seeing problems
with USB/SCSI external enclosures.

I haven't tried lately, but my USB/FireWire enclosure never worked
with Linux (or WinNT under firewire, sigh...) so I haven't touched it
in months. Money down the drain.

David> If you've verified this on 2.6.10, then you certainly have have
David> the ehci-hcd (re)queueing race fix that has made a big
David> difference for some folk. I don't know of any other issues in
David> that driver that could explain usb-storage problems.

I should try it again and see how it works under USB/Firewire, my last
attempts were under 2.6.[78] or so time frame.

John
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to XXXX@XXXXX.COM
More majordomo info at http://www.yqcomputer.com/
Please read the FAQ at http://www.yqcomputer.com/
 
 
 

[linux-usb-devel] 2.6: USB disk unusable level of data corruption

Post by Giuseppe B » Tue, 08 Feb 2005 01:20:09


I have a MAGNEX/ViPower USB/FirWire external HD enclosure. I
found that it works pretty fine (albeit slowly) when connected
to the USB 1.1 ports built in my Dell Inspiron 8200, but trying
to connect it via the Hamlet PCMCIA USB2 Card Adapter doesn't
work (it seems it gets assigned minors 1,2,3,4,5,6,... and so
on forever until I unplug it).

OTOH, I'm not sure if it's a PCMCIA adapter problem or USB2
enclosure problem. Indeed, if I don't load the EHCI modules,
and thus limit myself to the USB1.1 capabilities of the PCMCIA
adapters, I get other errors (I'll have to write a cleaner bug
report on this. And try the PCMCIA card with some other USB
device. Wish I could use my softmodem under Linux :(). (Using
kernel 2.6.10-3 from Debian.)

--
Giuseppe "Oblomov" Bilotta

Can't you see
It all makes perfect sense
Expressed in dollar and cents
Pounds shillings and pence
(Roger Waters)

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to XXXX@XXXXX.COM
More majordomo info at http://www.yqcomputer.com/
Please read the FAQ at http://www.yqcomputer.com/
 
 
 

[linux-usb-devel] 2.6: USB disk unusable level of data corruption

Post by David Brow » Tue, 08 Feb 2005 13:10:07


What do you mean "minors"? Addresses or actual /dev/sdN numbers?

If it's addresses, that would be an an enumeration problem. Some
recent changes have caused prolems there, 2.6.11-rc3-mm2 ought to
have a patch making it better. (Well, working around one of the
two problems that'd suggest.)

If it's actual /dev/sdN numbers, that would seem to be an issue
more at the level of usb-storage. Quite possibly related to the
bugs you didn't exactly detail (below).

- Dave




-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to XXXX@XXXXX.COM
More majordomo info at http://www.yqcomputer.com/
Please read the FAQ at http://www.yqcomputer.com/
 
 
 

[linux-usb-devel] 2.6: USB disk unusable level of data corruption

Post by David Brow » Tue, 08 Feb 2005 14:20:08

n Sunday 06 February 2005 6:55 pm, Rusty Russell wrote:

Not one I'd be familiar with, but that doesn't mean anything.

And I didn't see an "unusual_devs.h" entry for it, but it does
look to need the CONFIG_USB_STORAGE_HP8200e support, which I
see is labeled "experimental". I don't know how solid the
support for that is. But I see Greg's checked in a big patch
against the file with that driver, which should make the next
MM patchset against 2.6.11-rc3 ... mostly to support some
new hardware, but with that many changes I suspect there'll
be some bugfixes too.

This would be www.macpower.com.tw/produts/hdd2/daisycutter/dc_usb2
maybe? The www.qbik.ch/usb/devices database has a report from one
user saying they had problems with a different MacPower adapter until
they fixed its jumpers. Also worth a check.

- Dave



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

[linux-usb-devel] 2.6: USB disk unusable level of data corruption

Post by Giuseppe B » Wed, 09 Feb 2005 07:50:08

avid Brownell wrote:

Sorry, it's addresses.

usb 5-1: new high speed USB device using ehci_hcd and address 4
usb 5-1: new high speed USB device using ehci_hcd and address 5
usb 5-1: new high speed USB device using ehci_hcd and address 6

blah blah blah, neverending. So yes, it's probably the
enumeration problem.

Also, when I plug in the PCMCIA card I get (sorry for the
wrapping, Gravity sucks)

PCI: Enabling device 0000:07:00.0 (0000 -> 0002)
ACPI: PCI interrupt 0000:07:00.0[A] -> GSI 11 (level, low) ->
IRQ 11
ohci_hcd 0000:07:00.0: NEC Corporation USB
PCI: Setting latency timer of device 0000:07:00.0 to 64
ohci_hcd 0000:07:00.0: irq 11, pci mem 0x29000000
ohci_hcd 0000:07:00.0: new USB bus registered, assigned bus
number 3
hub 3-0:1.0: USB hub found
hub 3-0:1.0: 3 ports detected
PCI: Enabling device 0000:07:00.1 (0000 -> 0002)
ACPI: PCI interrupt 0000:07:00.1[B] -> GSI 11 (level, low) ->
IRQ 11
ohci_hcd 0000:07:00.1: NEC Corporation USB (#2)
PCI: Setting latency timer of device 0000:07:00.1 to 64
ohci_hcd 0000:07:00.1: irq 11, pci mem 0x29001000
ohci_hcd 0000:07:00.1: new USB bus registered, assigned bus
number 4
hub 4-0:1.0: USB hub found
hub 4-0:1.0: 2 ports detected
PCI: Enabling device 0000:07:00.2 (0000 -> 0002)
ACPI: PCI interrupt 0000:07:00.2[C] -> GSI 11 (level, low) ->
IRQ 11
ehci_hcd 0000:07:00.2: NEC Corporation USB 2.0
ehci_hcd 0000:07:00.2: irq 11, pci mem 0x29002000
ehci_hcd 0000:07:00.2: new USB bus registered, assigned bus
number 5
ehci_hcd 0000:07:00.2: USB 2.0 initialized, EHCI 0.95, driver
26 Oct 2004
hub 5-0:1.0: USB hub found
hub 5-0:1.0: 5 ports detected

The card only has 2 USB ports .. why 5 ports here? Is this the
same bug?

Another interesting tidbit is that I get:

USB Universal Host Controller Interface driver v2.2
ACPI: PCI interrupt 0000:00:1d.0[A] -> GSI 11 (level, low) ->
IRQ 11
uhci_hcd 0000:00:1d.0: Intel Corp. 82801CA/CAM USB (Hub #1)
PCI: Setting latency timer of device 0000:00:1d.0 to 64
uhci_hcd 0000:00:1d.0: irq 11, io base 0xbf80
uhci_hcd 0000:00:1d.0: new USB bus registered, assigned bus
number 1
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 2 ports detected
ACPI: PCI Interrupt Link [LNKC] enabled at IRQ 11
ACPI: PCI interrupt 0000:00:1d.2[C] -> GSI 11 (level, low) ->
IRQ 11
uhci_hcd 0000:00:1d.2: Intel Corp. 82801CA/CAM USB (Hub #3)
PCI: Setting latency timer of device 0000:00:1d.2 to 64
uhci_hcd 0000:00:1d.2: irq 11, io base 0xbf20
uhci_hcd 0000:00:1d.2: new USB bus registered, assigned bus
number 2
hub 2-0:1.0: USB hub found
hub 2-0:1.0: 2 ports detected

for the built-in ports ... I only have two USB ports on this
machine though, why does it see 4 of them?

(Do you also need the lspci and/or lsusb and/or dmesg of the
error that happens when I disable the EHCI driver and only let
the OHCI manage the PCMCIA card?)

--
Giuseppe "Oblomov" Bilotta

Can't you see
It all makes perfect sense
Expressed in dollar and cents
Pounds shillings and pence
(Roger Waters)

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