Re: [BUG] skge 0000:02:05: read data parity error

From: Adrian Bunk
Date: Mon Jan 14 2008 - 16:02:26 EST


On Mon, Jan 14, 2008 at 12:52:00PM -0800, Stephen Hemminger wrote:
> On Mon, 14 Jan 2008 20:57:49 +0100
> "Oliver Pinter (PintÃr OlivÃr)" <oliver.pntr@xxxxxxxxx> wrote:
>
> > Hi All!
> >
> > It is fully reproductable under 2.6.22.15, 2.6.23.13 (all tainted and
> > not tainted [4 different kernel] ) and 2 different PC:
> >
> > [BUG] skge 0000:02:05: read data parity error
> > [BUG] skge 0000:02:05: read data parity error
> >
> > steps:
> > 1. login as root
> > 2. start mc
> > 3. cd /sys/bus/pci/drivers/skge/0000:02:05.0
> > 4. press F3 (mcview) on resource0
> > 5. the system hang up, without panic or bug ... only this message
> > printed 2x: [BUG] skge 0000:02:05: read data parity error
>
> This is not a bug.
>
> The hardware has some debug registers that if accessed cause a read
> back to the host. Since this can point anywhere, it will cause errors
> or system hang.
>
> The point is don't do it.

Is it really a good idea that _reading_ files under /sys can kill your
machine?

That sounds like a huge trap for people debugging their machine (or e.g.
forgetting to exclude /sys from their backup).

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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