Re: [BUG 2.6.30+] e100 sometimes causes oops during resume

[Karol Lewandowski <karol.k.lewandowski@gmail.com>]

On Fri, Sep 18, 2009 at 12:27:37AM +0200, Rafael J. Wysocki wrote:
> On Thursday 17 September 2009, Graham, David wrote:
> > Rafael J. Wysocki wrote:
> > > I guess the driver releases its DMA buffer during suspend and attempts to
> > > allocate it back on resume, which is not really smart (if that really is the
> > > case).

> > Yes, we free a 70KB block (0x80 by 0x230 bytes) on suspend and 
> > reallocate on resume, and so that's an Order 5 request. It looks 
> > symmetric, and hasn't changed for years. I don't think we are leaking 
> > memory, which points back to that the memory is too fragmented to 
> > satisfy the request.
> > 
> > I also concur that Rafael's commit 6905b1f1 shouldn't change the logic 
> > in the driver for systems with e100 (like yours Karol) that could 
> > already sleep, and I don't see anything else in the driver that looks to 
> > be relevant. I'm expecting that your test result without commit 6905b1f1 
> > will still show the problem.
> > 
> > So I wonder if this new issue may be triggered by some other change in 
> > the memory subsystem ?

> I think so.  There have been reports about order 2 allocations failing for
> 2.6.31, so it looks like newer kernels are more likely to expose such problems.
> 
> Adding linux-mm to the CC list.

I've hit this bug 2 times since my last email.  Is there anything I
could do?

Maybe I should revert following commits (chosen somewhat randomly)?

1. 49255c619fbd482d704289b5eb2795f8e3b7ff2e

2. dd5d241ea955006122d76af88af87de73fec25b4 - alters changes made by
commit above

Any ideas?

Thanks.