Prev: GIT PULL] 9p file system additions for merge window
Next: Quota cleanups & fixes and ext3 fixes for 2.6.34-rc1
From: Stanislav Brabec on 8 Mar 2010 07:20
Cyril Hrubis wrote:

> Well I've seen empty lines when editing file with vim

And I have seen:

- Unreproducible SIGSEGV of gcc (while Wi-Fi connection over CF card was
running).
- Unreproducible SIGSEGV of opkg (downloading via Wi-Fi connection over
CF card).
- Unreproducible SIGSEGV of rm (called from find command launched via
ssh, networking via Wi-Fi connection over CF card).
(Hint: Tasks above are HDD-intensive.)
- Lost blocks while copying from CF to SD.
- Lost blocks while copying from HDD to SD.
- Lost blocks while copying from CF to USB flash stick.
- And I see display noise while CF Wi-Fi card is active.

These problems appear in all kernels, at least since 2.6.26.

There is no note in the syslog.


________________________________________________________________________
Stanislav Brabec
http://www.penguin.cz/~utx/zaurus

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
From: Russell King - ARM Linux on 8 Mar 2010 07:50
On Mon, Mar 08, 2010 at 01:16:35PM +0100, Cyril Hrubis wrote:
> Hi!
> > - And I see display noise while CF Wi-Fi card is active.
>
> Forgotten about this one. See for yourself, notice short black vertical lines
> flashing randomly.

I haven't looked at the video.

Is this display rotated by 90 degrees?

If so, they're actually horizontal lines as far as the display scanning
is concerned - and that tends to suggest that there's insufficient system
bus bandwidth for all the activity taking place, and the LCD controller
is being starved of data.

I've seen similar (described) effects on SA1110 systems in past years
with low clock rates.

Some of the reports suggest that this happens with multiple kernel versions
and is not something new to the latest kernels. Please confirm when the
problem started.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
From: Cyril Hrubis on 8 Mar 2010 08:40
Hi!
> Is this display rotated by 90 degrees?

Yes it is.

> If so, they're actually horizontal lines as far as the display scanning
> is concerned - and that tends to suggest that there's insufficient system
> bus bandwidth for all the activity taking place, and the LCD controller
> is being starved of data.

Well, when doing 'echo 0 > /sys/class/graphics/fbcon/rotate_all' for 2.6.33
I've got the same problem but the lines are vertical. However 2.6.24 seems to
work in non rotated mode.

> I've seen similar (described) effects on SA1110 systems in past years
> with low clock rates.
>
> Some of the reports suggest that this happens with multiple kernel versions
> and is not something new to the latest kernels. Please confirm when the
> problem started.

As far as I can test in rotated mode it happens for kernels from 2.6.24 to
2.6.33 (I haven't older kernel than 2.6.24 that boots on spitz).

--
metan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
From: Andy Green on 11 Mar 2010 08:30
On 03/08/10 08:25, Somebody in the thread at some point said:
> Hi!
>> dmesg would not be useful, it usually hits user programs. Like... mutt
>> suddenly displaying , instead of - in the header. Program failing to
>> start because function printg is not found (it was not exactly
>> printf->printg, I don't remember exact symbol), ping complaining
>> about discarding corrupted packets, etc.
>>
>> (Or of course, kernel oopsing or not going from suspend at all. But as
>> even user data are being corrupted, oops is not likely to be
>> interesting and system is typically not in state to capture it any more.)
>>
>
> Well I've seen empty lines when editing file with vim (these that are starting
> with blue tilda) in the middle of file. And sometimes programs segfaults for no
> good reason. Just today I've run "apt-get update" and got:
>
> symbol lookup error: apt-get: undefined symbol: _ZN16pkgAcquireStatus4StopEv
>
> While the correct symbol seems to be _ZN16pkgAcquireStatus4.
>
> When running 'make' in kernel directory and closing the display sometimes
> machine dies and nothing but reset under battery cover helps. I remeber waking
> up in the morning, opening the device and reseting the device. And it seems to
> be provoked much more by active CF wifi card.

I saw very similar failures for a long time on our iMX31 based device.
Eventually I found a Freescale errata where the RAM inside the USB2
macrocell started to make single bit errors below 1.38V Vcore; ours was
1.4V at that time but dipped on CPU load.

I cranked up the Vcore to 1.6V and that solved it, we also added some
ceramic caps to Vcore to help with the dips.

So it might be worth looking at PMU arrangements for Vcore level / look
for dips with a 'scope (despite this isn't an iMX31).

A characteristic of it was it never caused kernel issues, since the
kernel didn't come over USB. It only ever caused troubles on userspace
stuff.

-Andy

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
From: Stanislav Brabec on 11 Mar 2010 10:50
Andy Green wrote:

> I saw very similar failures for a long time on our iMX31 based device.
> Eventually I found a Freescale errata where the RAM inside the USB2
> macrocell started to make single bit errors below 1.38V Vcore; ours was
> 1.4V at that time but dipped on CPU load.

Good tip. It seems that nobody ported driver for the voltage control
chip ISL6271 from 2.4 kernel, and bootloader probably does not set
correct values.

Datasheet:
http://www.penguin.cz/~utx/zaurus/datasheets/power/Xscale/ISL6271.pdf

--
Stanislav Brabec
http://www.penguin.cz/~utx/zaurus

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
First  |  Prev  |  Next  |  Last
Pages: 1 2 3 4
Prev: GIT PULL] 9p file system additions for merge window
Next: Quota cleanups & fixes and ext3 fixes for 2.6.34-rc1