Query dw_dmac driver: All descriptors done, but channel not idle!

[Viresh KUMAR]

On 6/18/2010 7:22 PM, Haavard Skinnemoen wrote:
> Viresh KUMAR <viresh.kumar at st.com> wrote:
>> Can somebody please confirm, if it a known issue or not? Or if there
>> are some solutions for this problem.
> 
> I'm not aware of any such issue. The code was added as a purely
> defensive thing; when writing it, I just thought about what might
> happen if we go through all our descriptors without finding the current
> one, and added some code to report the issue and try to recover.
> 
> I suppose it might be caused by some issue with the peripheral itself,
> but I think it's more likely to be caused by some race condition in the
> driver, i.e. something goes wrong when inserting or removing
> descriptors in the chain.
> 
> What might be very good to know at this point is the value of
> the llp variable, and perhaps also the value of the CH_EN register to
> see if the channel is idle or not.
> 

Thanks Haavard,

Will debug it further.

viresh.