On 11/18/12 5:06 PM, "NeilBrown" <ne...@suse.de> wrote:

>
>Hi Dan,
> could you comment on this please?  Would it make sense to arrange for
>errors
> to propagate up?  Or should we arrange to do a software-fallback in the
>dma
> engine is a problem?  What sort of things can cause error here anyway?

Propagating up is missing reliable "dma abort" operation.

In these cases the engine failed to complete due to hardware hang / driver
bug, or has hit a memory error (uncorrectable even with software
fallback).  This originally should have been using async_tx_quiesce()
which also does the panic.

The engines that I have worked with have either lacked support for
aborting, or were otherwise unable to recover from a hardware hang.
However, for engines that do support error recovery they should be able to
hide the failure from the upper layers.

--
Dan

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

Reply via email to